PAGER

A. Latar Belakang

Pager merupakan salah satu alat telekomunikasi yang dulu pernah sangat booming. Alat telekomunikasi adalah sebuah alat elektronik yang memungkinkan menyampaikan informasi dan pesan dari suatu tempat ke tempat lainnya dengan jarak yang terkadang tergolong cukup jauh. Dan pager tentu mampu melakukan hal tersebut,walaupun dalam realitanya ketika berkomunikasi dengan menggunakan pager kita tidak bias menerrima feed back  secara langsung dan cepat.

Sebagai alat komunikasi yang dulu pernah sempat diidola idolakan pada tahun 1990-an ,termasuk di Indonesia. Bahkan dulu sempat dijadikan sebuah lirik lagu “ tit…. Tit… tit….pager ku berbunyi…….”, tidak ada salahnya jika kita mengetahui seluk beluk tentang teknologi pager itu sendiri, karena saya rasa tidak semua orang tahu bagaimana munculnya pager itu sendiri, lalu bagaimana perkembangannya, cara kerjanya, bagaimana protokolnya, hingga bagaimana pager pada masa abad 21 yang lebih modern ini.

Menurut saya , karena dewasa ini pager khususnya jarang sekali ditemukan pemakainya ( mengindikasikan tidak lagi diminati ), mungkin hal ini yang membuat sebagian orang enggan mencari informasi tentang pager itu sendiri, untuk itu dalam materi yang saya susun ini saya menyusun sebuah materi yang memuat seluk beluk pager, sebagai tambahan pengetahuan bagi rekan-rekan .

 

B. Tujuan

            Diharapkan dengan disusunnya materi tentang pager ini dapat memberikan informasi kepada khalayak luas mengenai  telekomunikasi pager itu sendiri , mulai dari sejarahnya, cara kerjanya, protokolnya, kenapa pager yang dulu sempat booming ternyata akhir akhir ini khususnya di Indonesia terus merosot atau kurang diminati lagi oleh masyarakat, hingga bagaimana perkembangan pager pada abad 21 ini,

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PEMBAHASAN

 

A. Definisi Pager

Pager (biasanya disebut sebagai beeper )  adalah salah satu media penerima pesan yang portable , yang terbentuk dari perpaduan dari perkembangan teknologi komunikasi dan teknologi informasi, dan merupakan simple personal telecommunication device yang berguna untuk menerima pesan singkat

Secara sedarhana pager bekerja berdasar prinsip kode signal radio yang ditransmisikan melalui suatu provider (Penyedia jasa layanan) atau bisa disebut juga secara singkat bahwa pager adalah alat yang digunakan untuk menghubungi seseorang melalui jaringan tertentu, dimana operatornya adalah  melalui manusia.

 Sebuah one – way numeric pager hanya dapat   menerima sebuah pesan yang terdiri dari sedikit  angka dan huruf yang secara khas sebuah nomor biasanya mengharap untuk ditelephone .Lalu juga terdapat  Alphanumeric pagers.

 Pager  sebagai  alat telekomunikasi yang hanya mampu menerima pesan saja, dimana proses adanya feedback atau umpan balik dari pesan yang disampaikan harus melalui beberapa proses terlebih dahulu.

 

Pager, jika kita analogikan hampir mirip dengan handphone, namun bedanya adalah pager hanya bisa menerima SMS dan tidak bisa mengirim SMS, seperti layaknya handphone yang serbaguna yang ada saat ini.

 

Pager berperan sebagai common personal and mobile Comunication hingga  adopsi mobile phone menjadi booming di akhir tahun 1990-an. Namun realitanya saat ini bisa kita lihat bahwa pager mengalami kejatuhan dan terpuruk dalam keusangan dan hanya dipertahan oleh pasar sempit , bukan pasar massal lagi, misalnya hanya dipergunakan untuk emergency service personnel, medical personnel, dan information technology support staff.

 

 

B. Sejarah Perkembangan Pager

            Menurut sumber dari WIKIPEDIA bahwa Pager ditemukan oleh Multitone Electronik pada TAHUN 1956 di St Thomas’ Hospital, London.

            Tetapi  ada yang menyatakan bahwa Terobosan  tentang pager muncul pada tahun 1949 , saat di adopsinya two- ways radios menjadi one- way cordless remote telephonic signaling, ini juga dianggap penemuan pertama dari telephone pager System, penemuan ini digunakan untuk dunia kedokteran, tetapi  hambatan terjadi karena adanya beberapa dokter dan paramedic, yang khawatir system pager ini dapat menimbulkan rasa kesal dan tidak nyaman pada pasien. Penemuan ini terjadi di New York. Teknologi  one way radio signaling ,yang sama  juga digunakan pada orang yang bertugas membuka pintu garasi.     

Namun, lebih jauh lagi ada sumber informasi lain yang menyebutkan bahwa Pada tahun 1921, pager telah dikenal dan digunakan oleh kepolisian detroit di Amerika untuk keperluan pemanggilan yang darurat. Pager pada saat itu lebih dikenal dengan sebutan ‘beeper’.

Istilah Beeper yang kemudian menjadi  ‘pager’ ,mulai  dikenal sejak tahun 1959, sejak Motorola membuat produk berupa alat penerima pesan yang kecil dan portable hingga mudah dibawa oleh pemiliknya yang tidak lain adalah pager

Memang Tujuan awal mulanya pager ini berfungsi untuk memberikan panggilan kepada Dokter di Rumah Sakit, ketika ada keadaan gawat darurat. Sejak saat itu pager mulai dikembangkan dalam bentuk yang diusahakan lebih baik dan  lebih sophiscation. Dengan pager ini jutaan pesan di sampaikan kepada orang yang memiliki pager dari orang yang menyampaikan pesan, dengan konsep komunikasi pesan yang bisa dipercaya.

Pada tahun 1980-an alat komunikasi pribadi yang dianggap canggih adalah radio panggil (pager) ini.  Di Indonesia  sendiri pager baru dikenal pada awal tahun 1990-an

            Di dunia pager ada dua perbedaan kategori system operasi pager. Dimana salah satunya ialah One – site paging System yang digunakan di rumah sakit untuk menyakinkan beberapa informasi penting yang darurat, pager kategori system ini di temukan pada tahun 1956, dan merupakan jenis pager yang pertamakali ditemukan. Sedangkan tipe pager yang lainnya atau tipe pager yang kedua adalah Wide Area Paging. Wide Area Paging ini, menawarkan features yang hampir sama dengan pager bertipe One –Site Paging, tetapi Wide Area Paging ini menjangkau sebuah kota atau wilayah atau Negara, yang jelas jangkauannya lebih luas daripada jangkauan pager yang dipergunakan pada rumah sakit.

Sebuah  wide area paging service processing method untuk radio paging system dihubungkan ke  public switched telephone network dan memiliki sebuah paging sistem yang mampu menstramisikan data sebuah radio paging signal. wide area paging service processing method meliputi tahapan : permintaan sebuah wide area call processor, yang menyatakan paging sistem untuk  process a wide area call , saat sebuah panggilan diterima ke paging system , walaupun  public telephone network dimatikan; membaca sebuah data base seorang korespondensi pelanggan mengemas informasi  wide area paging message , saat wide area call process diminta;  kemasan informasi the wide area paging message  dikirim sebuah sinyal pesan pada accordance dengan sebuah kelas  wide area service untuk sebuah korrespondensi area paging system selesai mentransfer sebuah bagian pesan; and penampilan dari wide area radio call untuk corresponding pager subscriber, setelah  pesan wide area paging diterima pada corresponding area paging system and kemudian sebuah frekuensi panggilan, yang seharusnya disinkrontkan oleh pada perpindahan area oleh panggilan pelanggan.

Dulu  pengoperasian pager  bergantung pada frekuensi radio AM, kemudian pager berpindah pada frekuensi FM hingga  bentuk komunikasi ini menjadi ada dimana-mana, dan menunjukkan perkembangannya. Pada kasus yang sama, sebelumnya ditemukannya  system telephone selular, pager digunakan sebagai pengganti untuk pelayanan telephone local dan internasional yang lebih murah, dibandingkan menggunakan telephone selular secara langsung.

            Sebagai sedikit tambahan pager Motorolla Alphanumeric digunakan di Brazil pad atahun 1990 an, pager ini di operasikan oleh teletrim.

            Layanan pager ini menawarkan kepada pelanggannya sejumlah jenis rencana rencana dan pilihan sesuai dengan kebutuhan pelanggan dan jenis alat atau pager yang digunakan. Pada umumnya, semua pager diberikan nomor telephone yang unik, saat alphanumeric pagers diberikan sebuah alamat email, biasanya terdiri atau terdapat nomor telephone.

            Pada sebuah tanda nomor panggilan nomor, sekelompok panggilan ditangkap sebuah sejenis greeting asking the caller untuk memasuki sebuah pesan dan terkadang memberikan penelphone sebuah pilihan untuk meninggalkan voice mail. Biasanya , dalam beberapa menit, paged person  akan menerima sebauh tanda dari pager dengan nomor telephone untuk kembali menelphone dan atau sebuah kode pager. Pada kasus email paging, akan ditunjukkan tampilan  teks.

 

Berikut ini adalah beberapa jenis pager :

  • Numeric pagers  jenis pager sedarhana yang menawarkan hanya sebuah tampilan numeric dari nomor telephone yang untuk dipanggil dan kode pager.
  • Alphanumeric pagers adalah esensi  versi modifikasi dari versi numeric pager dengantampilan yang sophisticated untuk mengakomodasi teks. Alat ini biasanya memberikan sebuah alamat email untuk menerima tex pesan.
  • Two-way Alphanumeric pagers  adalah alphanumeric pager dengan kemampuan untuk mengirim tipe pesan text dengan keyboard yang kecil.

Hampir semua semua system pager modern menggunakan simulcast yang dibawa oleh  controlled networks. System type of distributed membuat mereka tidak bisa dipisahkan lebih dari yang dapat dipercaya daripada terrestrial berdasarkan cellular networks untuk mengirim pesan.  Banyak paging transmitters  boleh saling melengkapi sebuah  coverage area, ketika atau saat  cellular systems  dibangun untuk mengisi lubang atau celah  pada existing networks. Saat  terrestrial networks berada dalam masalah , satellite systems tetap terus berlanjut  untuk beroperasiper, karena penembusan superior building dan  ketersedian layanan dalam situasi genting ataupun ketika ada bencana. Pagers biasanya digunakan oleh responden dalam situasi genting.

 

C. Cara Kerja Pager Seacara Sedarhana

Berikut ini cara kerja penggunaan pager:,
Pesan yang dikirim oleh pengirim yang melalui provider service pager yang ditujukan pada ID atau nomor pager tertentu, adapun urutan secara sistematis ( pada umumnya ) mengenai pengiriman pesan melalui provider service pager ialah :

 

1) hubungi operator pager tersebut dari telfon rumah (biasanya nomer      operator ada di belakang pager tersebut.)

2)        Setelah terhubung dengan operator, operator akan meminta Id dari pager yang akan di tuju.

3)        Kemudian pihak yang akan menyampaikan pesan ke pager tujuan membacakan pesan yang akan di kirim.

4)        Lalu sebelum operator mengirim pesan ke pager tujuan, operator akan mengulangi pesan yang telah anda sampaikan.

5)        Terakhir pesan terkirim ke pager tujuan

 

 Setelah pesan telah diterima oleh penerima pesan maka alarm atau tanda berbentuk getar akan berbunyi atau bergetar dan pesan tersebut akan tampil di layar LCD yang terdapat dalam pesawat pager. Pesan dapat diterima selama masih dalam service area dari provider yang bersangkutan.

 

 

 

D.Perkembangan Pager Protocols    

 

One Way Pager Protocols

Sebuah pager didisain untuk menerima paging signal yang ditransmisikan dibawah kontrol pager terminal. Paging signal ini didisain untuk membawa informasi pager-specific address,  sehingga memberi tanda pada pager secara individual. Selain itu, data pesan ditunjukkan sebagaimana sebuah indikasi, jika sebuah tanda bunyi yang khusus dibentuk sebaiknya terdengar kembali pada pager. Karena traditional pager (one-way pager) tidak memiliki kemampuan meminta retransmisi pada saat terjadi gangguan atau juga sebuah kesalahan, informasi ini harus ditransmisikan pada beberapa bentuk yang terpercaya kepada penerima.

Perusahaan yang berbeda telah mengembangkan sebuah susunan teknik untuk membalas informasi penting kepada remote pagers. Teknik ini , dikenal sebagai encoding formats, yang didefinisikan teknik yang bekerja untuk merepresentasikan informasi protocol element data sebagaimana menginterpretasikan semua isi data secara baik. Sebagai contoh dalam  encoding format adalah data  dikirim sebagai arus  sepasang digits. tiap digit dipresentasikan oleh kotak gelombang. Tiap pasang nol direpresentasikan oleh sebuah gelombang dengan periode 2,0 miliseconds. Disamping itu sebuah binary atau pasangan gelombang direpresentasikan  sebuah bentuk gelombang dengan period 4,0 milisecond. Digital paging technique lainnya ,  gelombang sinus ditransmisikan secara berkelanjutan; jika phase sinyal ini tidak diubah dari sebuah daur untuk selanjutnya, kemudian ini merepresentasikan rangkaian 11 atau 00. jika tahap gelombang sinus selanjutnya dikembalikan, kemudian ini merepresentasikan rangkaian 10 atau 01.

Pada banyak kasus, encoding format mengirim data tambahan, yang dikenal sebagai Error Detection and Correction  Codes, yang mampu menditeksi dan menemukan kesalahan penerimaan data. Dengan mengoreksi kesalahan , pager mencetak  suatu hal yang dapat dipercaya  yang dikembangkan secara dramatis.  Baik  analog, maupun  digital transmission techniques  digunakan untuk mengirim atau mentransfer data ke pager.

Hampir semua paging format adalah manufacturer-specific dan sering  proprietary ( hak milik ).  Itu adalah sedikit dari paging protocols , yang telah dikembangkan dan ditempatkan pada public domain, sehingga banyak perusahaan yang berbeda dapat bersaing menciptakan compatible pagers. Diantara   public domain protocols ini adalah  POCSAG, Swedish Format (MBS), the Radio Data System (RDS) format and the European Radio Message System (ERMES) format. Each of these formats were developed in Europe.

Tiap perbedaan paging formats , tentu memiliki keuntungan dan kerugian masing –masing , saat dibandingkan satu sama lain. Pada beberapa paging networks yang didisain untuk mendukung pager yang tidak hanya diperoleh  dari bawaannya, tetapi juga diperoleh dari electronic and department stores, paging terminal  haruslah mendukung  multiple paging formats. Pada kasus dimana bawaan telah dikontrol dengan sebaik mungkin oleh pelanggan, network dapat dibatasi untuk sedikit ,format yang berbeda. Perusahaan telah merancang format mereka dengan cara berusaha menghindari  “ kesalahan “ tanda panggilan dari pager,  buatan perusahaan lainnya, saat sebuah format pada frekuensi yang sama, dimana disana terjadi penggabungan paging format untuk menyediakan metode transmisi  paling efficient, semua data terkirim secepat mungkin.  

Hamper semua pager selalu  “powered on” , sehingga mereka dapat menerima sebuah halaman pesan disetiap waktu. Pemeliharaan saluran kekuatan pada pager akan meningkat intervalnya antara  charging or replacing of the battery. Dalam sebuah usaha untuk battery  yang hap selanjutnya hidup secara maksimal, tiap pager dan paging format biasanya petugasnya  beberapa “battery saver” technique yang mengizinkan pager untuk memasuki sebuah kekuatan yang lemah untuk jangka pendek atau singkat. Mengikuti tahapan yang menggambarkan bagaimana paging information diformat dibawah berbagai jenis  encoding techniques.

Two-Tone Format

Salah satu format radio paging yang terakhir diluncurkan digunakan sebuah teknik yang dikenal sebagai Two-Tone to alert pagers. Teknik two-tone analog paging mentransmits dua percontohan audio tones, biasanya perbedaan durasi tone audio , untuk menunjukkan sebuah keunikkan pager address. Sejumlah nada yang digunakan  menentukan jumlah maksimum pager yang dapat didukung. Pada sebuah sistem yang mendukung adanya 30 nada yang berbeda ( karena tiap nada memang harus berbeda ) , 30 x29 atau 870 perpedaan pager dapat didukung atau dapat tersedia pada pager. Nada pada kisaran 500 Hz hingga 4,00 Hz adalah jenisnya. Sebagai contoh , kombinasi frekuensi 3,636 Hz diikuti 880Hz jenisnya akan menandai atau memberi tanda sinyal pager. , saat rangkaian 880 Hz diikuti oleh  3,636 Hz akan menandai atau memberi sinyal pada sebuah pager yang berbeda. Banyak dalam waktu tertentu , pager memerlukan sebuah periode waktu yang pendek antara dua nada , yang dikenal sebagai “ the Gap ” untuk pengoperasian yang lebih baik. Sebagai tambahan , gap lainnya dalam keadaan normal diperlukan setelah nada kedua, sebelum dua nada rangkaian lainnya ditransmisikan pada kepentingan pager lainnya. Timing diagram untuk  paging format ini terlihat seperti yang dibawah ini:

 

t 1

t 2

t 3

t 4

Tone A

Gap A

Tone B

Gap B

 

Pada beberapa two-tone pagers, panjang transmisi daata dan periode waktu dari gap kontrol tanda bunyinya dapat didengar. Pada beberapa implementasinya , nada “B” diulang dengan sebuah interval pendek sehingga menyebabkan tanda bunyi terdengar double In some implementations, the “B” . nada t1 and t2 periode waktunya bersifat khusus yaitu hingga 240 millesecond. . Gap A adalah  0 to 10 milliseconds, and Gap B adalah 500 ms.olehkarena itu , sebuah page yang khusus dengan mudah mengambil lebih dari satu detik.

 Two tone encoding format digunakan untuk nada hanya sebagai nada dan voice paging. Jika sebuah voice page ini, setelah ditransmisikan nada B dan menunggu periode Gap B, pembicara pager dihubungi secara langsung ke sinyal analog sehingga anolog voice signal terdengar pada pager. Pada banyak kasus, itu terjadi hingga pengguna menekan sebuah tombol untuk mematikan suara pesan yang terdengar, jika ini tidak dilakukan , pager bertindak seperti sebuah nada radio untuk paging frequency dan itu akan membuat  pengguna untuk mendengar semua paging signals and suara pesan yang dikirim.

 Two-tone format  memiliki beberapa  drawbacks due  untuk membatasi jumlah pager yang dapat didukung pada satu radio frequency, and the excesive  long tone and periode gap. Menurut standart , saat ini  encoding format  bekerja dengan lambat. Banyak  dari sistem format ini karena tergolong pager tua yang masih dalam jaringan. Bagaimanapun , saat diwaktu itu diambil untuk mentransmit  sebuah  single tone only page,  paging formats lainnya dapat mengirim sebanyak 60 tone page.

Five/Six Tone Format

The Five/Six tone analog paging format was an improvement on the two-tone format. The format uses 11 different tones; ten of these tones represent the digits 0, 1, 2, up to 9. The eleventh tone is known as the Repeat, or “R” tone. Up to 100,000 pagers can be supported with these 11 tones. Every pager is assigned a number from 00,000 to 99,999. To alert the pager, the five tones that define its number are transmitted sequentially; to alert pager 15243, the five tones representing these five digits are sent in a row.

The specifications only define the minimum time period of a tone and not necessarily the maximum period. If a pager number has repeated digits, it is not possible to determine if this is a repeated digit or just a long tone. Therefore, the “R” tone is introduced. When this tone is heard, it is assumed that the prior digit is being transmitted again. If the digit is repeated a third time, the original tone is transmitted. To alert pager 11333, the tone sequence 1R3R3 is transmitted. An optional twelfth frequency can be transmitted after the five-digit number is sent. This sixth digit indicates that a different beep pattern should sound.

To preserve battery life, five-tone pagers are grouped into one of ten battery-saver groups. It is up to the paging terminal equipment to “batch together” all page alerts by battery-saver group. Prior to alerting each of the pagers in a group, a single long tone known as “the Preamble,” is transmitted first. This preamble is one of the ten audio frequencies that represent the ten digits. The preamble “wakes up” all of the pagers in this battery-saver group to look for its specific five-tone sequence. If the battery-saver tone is not heard, the pager can “go back to sleep” for a while, occasionally looking to see if its particular long tone is being transmitted.

With the addition of the battery-saver tone, one million pagers can be supported by the format. The actual time to transmit a single page within a batch of pagers typically is in the order of 225 milliseconds (not amortizing the time taken to transmit the common preamble code). Therefore, more than four times the number of tone-only pagers can be supported on a single channel utilizing the 5/6 tone format as can be achieved under the two-tone paging format. The 5/6 tone format can support tone only as well as tone and voice paging.

Golay Format

The Golay paging technique is a proprietary encoding mechanism that was developed by Motorola Inc. This is a digital encoding mechanism, meaning that the paging information is represented by signals that can be interpreted as a stream of zeros and ones. It is up to the pager to receive this data stream and to extract pager-specific information from this transmission.

The Golay format is capable of transmitting tone only, numeric, alphanumeric and voice pages. Much thought was put into the development of the format so that the information is transmitted in such a way as maximize the probability that the data will be received intact. Error-correcting codes are transmitted along with the data so that even if a number of data bits are received incorrectly, the pager can detect and ignore this incorrect data and replace it with the proper information. To further improve reception probability, data bits are transmitted in a particular order to reduce the probability that if a short radio burst corrupts sequential data, the entire data sequence can be recovered correctly.

For purposes of improving battery life and avoiding false alerts due to other encoding formats sharing the same frequency, pagers are divided into groups. A preamble code,as in 5/6 tone paging, is transmitted prior to page alerts. Only pagers that fall within the group number specified by the preamble code transmitted need look for their particular pager address within the stream of paging data that follows.

To improve page alert reliability while making pager message transmission move quickly, the pager address information is transmitted at 300 bits per second while any numeric or alphanumeric data transmitted to the pager is sent at 600 bits per second. The function code of the pager that determines one of four beep patterns associated with the particular pager address is encoded as part of the pager address information that sent. Many page alerts consisting of address and message data can be transmitted sequentially directly following the common preamble code for a group of pagers. This”batching” technique amortizes the time it takes to transmit the preamble code over a number of individual page alerts.

The combination of information encoding techniques, variable transmission speed, sending of pages back to back, batching, the order in that data bits are transmitted, and the use of the Error Correcting Codes to detect and correct corrupted data makes Golay a reliable, efficient protocol that performs well during short bursts of radio interference. To compare the transmission speed of Golay relative to analog 5/6 tone encoding, in the Golay encoding technique an individual tone-only page can be transmitted in approximately 202 milliseconds, including its error detection and correction data. Therefore, in less time than it takes to send a 5/6 tone, encoded, tone only page, a more reliable transmission of a Golay tone-only page can be sent.

NEC-D3 Format

The NEC-D3 encoding format was developed by NEC America for use in its R3-D3 pagers. This digital encoding mechanism is capable of transmitting tone only or numeric pages. Information is transmitted to the pager at the rate of 200 bits per second. For purposes of conserving battery life, two techniques are used. First, prior to transmitting any page alerts under this encoding mechanism, a special preamble is sent, signaling all pagers that page alerts are coming. Until this preamble is detected, the pagers remain in a reduced power mode. The second technique used is to divide the pagers into four groups based on the address of the pager. A fixed amount of transmission time and, therefore, a fixed amount of bits to be transmitted, is allocated to each of the four groups. As many encoded pages and their associated messages as can fit within the number of bits allocated to each group may be transmitted at one time. If there are not enough pages to fill to group, “idle codes” are filled in. Idle codes are ignored by all pagers.

The four fixed time periods are allocated back to back following the preamble. Therefore, if a pager’s address indicates that it falls within group four, the pager can almost completely power down during the transmission time for Group One, Group Two and Group Three. Likewise, a pager within Group One will remain powered up looking for its unique pager address, but after the fixed time period for Group One has passed,the pager can power down during the time allocated to Groups Two, Three and Four. Error-correcting-code information is transmitted with each pager address and each block of message information. An extra data bit also is transmitted with address and message data so that the total number of “one” bits in each transmission block always is even. This extra data bit is known as the “even parity” bit. The parity checking adds yet another manner of detecting transmission errors.

Address and message data is transmitted in blocks of 32 bits. Each address consists of 20 data bits, 10 check bits and 1 parity bit. Each message data block also consists of 20 data bits, 10 check bits and 1 parity bit. Each 20 bit data block can contain 5 digits of a numeric page. There are 20 blocks of 32 bits that are transmitted for each group. Therefore, each group is allocated 3.275 seconds to transmit its pages.

Each individual tone-only page in NEC-D3 is transmitted in 160 milliseconds. This does not consider the amortization of the preamble code or the delays that may been countered to transmit the prior group if this was the only page to send. In a system with a large paging volume consisting of pagers that are evenly spread across the four groups, NEC-D3 can be a fast transmission protocol.

POCSAG Format

The POCSAG encoding format was developed during the period from 1975 to 1978 by a group of international engineers who were looking to create a mutually agreeable code for wide-area paging. Because the meeting was chaired by the British Post Office, and the group was known as the Post Office Code Standardisation Advisory Group, the acronym POCSAG was adopted. Official international recognition by the international standards organization known as the CCIR in February 1981 adopted the POCSAG standard as Recommendation Number 584, Radiopaging Code 1. This encoding format has been implemented by a large number of manufacturers around the world.

POCSAG is a digital encoding format that is specified to operate at 512 bits per second. The paging format has also been implemented, without modification to the encoding mechanism, to operate at 1200 bits per second. During 1991, successful paging operations have been reported at 2400 bits per second (refer to a later section of this chapter regarding the Telocator High Speed Paging Committee). The higher speeds allow more pages per second to be transmitted and can therefore support a larger customer base over a single channel than lower speeds. A mix of speeds can be supported over one frequency. Pagers are fixed to operate at a single speed; even at the slowest speed and under high traffic volumes, POCSAG can support approximately 15 tone-only pages per second. For comparison purposes, a single tone-only page at the slowest rate (not considering preamble and batching overhead) requires 62 milliseconds. At 1200 bits per second, only 27 milliseconds are required to send a page;at 2400 bits per second, only 13 milliseconds are required. With the introduction of high speed POCSAG, paging systems have increased the number of page alerts that can be delivered in any period of time almost 100-fold from the early days of only two-tone paging.

The POCSAG coding format can support up to 2 million individual pagers. Tone-only,numeric and alphanumeric paging are supported, and up to four beep patterns can be associated with each pager address.

POCSAG can be very efficient when transmitting large volumes of traffic. In systems with a mixture of encoding formats and light loads of POCSAG pagers, the format can be inefficient and can waste air time.

Every POCSAG pager falls into one of eight pager groups based on pager address. A POCSAG transmission consists of a 576-bit preamble code that is used to “wake up” pagers that are in a battery-saver mode. A batch of pages consist of a synchronization code followed by eight transmission “frames.” A frame is a fixed number of bits that begins at a fixed time duration after the transmission of the sync code. Each frame is transmitted back to back following the sync code. After the eighth frame is transmitted,the next batch consisting of a sync code and eight more frames can be sent.

A pager that falls into a particular group may only be paged by placing its pager address within the particular frame number fixed for that pager (thus creating the eight groups). If there is no room to put the pager address within a frame, then the pager can not be alerted until that frame number comes around in the next batch, and there is room to put that pager address within that frame. No more than two pagers can be alerted within one frame but, in numeric or alphanumeric paging-only systems, only one pager can be alerted in a frame. Any message data for a pager is encoded and transmitted in fixed blocks, known as “codewords,” starting directly after the codeword that contains the pager address. Most times the encoded message information is transmitted across many frames, thus blocking other pages from being placed within these frames. It is up to the paging terminal to pack tone-only, numeric and alphanumeric information for different pagers within frames in the most efficient manner possible to minimize the total number of frames required to output a given number of page requests. Inefficient packing mechanisms can increase the airtime required to send a particular number of pages.

All pager address and message information have an error detection and correction code associated with it to detect small error bursts and to correct single bit errors that may occur within a single codeword. The error detection and correction mechanisms of POCSAG do not perform as well as those of Golay over long streams of bits because of the better error codes used within Golay and the order in that Golay transmits its address and message information.

Because of its speed, efficiency, the number of pager manufacturers with compatible pagers available and its international acceptance, POCSAG has become a popular paging format in high-volume paging applications.

Mark IV/V/VI Formats

The Multitone Electronics Mark IV, V and VI encoding formats are digital formats, and can accommodate tone only, numeric display and voice paging. Unlike other digital formats that transmit a fixed number of binary ones and zeros in a fixed period of time, these formats require 2 milliseconds to transmit a binary 0 and 4 milliseconds to transmit a binary 1; the data transmission rate varies between 250 and 500 bits per second. Up to 100,000 pagers can be supported over a single frequency, and up to eight different beep patterns can be specified for each pager.

The Mark IV format was designed to transmit tone-only pages, to forward a single digit to a pager or to forward up to four digits to a pager depending on the way information is encoded. Multitone pagers using the Mark IV format can display one digit and sequentially display four digits. Pagers utilizing the Mark V pager provided a five-digit display and could display up to ten digits. These pagers have been used extensively within hospital private paging systems.

The Multitone pagers using the Mark VI format are capable of displaying a ten-digit message; this format also provides a means for the paging terminal to periodically transmit the time of day. When not displaying a message, the pager will display the time continually; this time remains accurate for short periods and is adjusted when the paging terminal sends its next update. The time-of-day transmissions also are used to determine if the pager has moved out of range of the transmitter. If the periodic page is not detected, the pager will alert the user that it is “out of range.” Prior to transmitting page alerts, a preamble is transmitted that takes the pagers out of a battery-saver mode; page alerts then are transmitted back to back. Because of the time to transmit a binary “1” is double the time for a “0,” the duration of a tone-only page depends on its address. A single page alert can be transmitted in 224 to 276 milliseconds.

A single page alert is created from a stream of four-bit fields. Each digit of the pager number and each digit of the message is encoded within a single four-bit field. The pager function information that determines the beep pattern (indicating if one, four, five or ten digits are being sent; if this is time-of-day data; and if speech will follow) is encoded within other four bit fields in the Mark paging formats.

Parity information is transmitted as a means of determining if a bit has been corrupted during transmission. Odd parity bits are bits that are set to “0” or “1” so that the total number of “1” bits within segments of the format always will add up to an odd number. For further error detection, the pager address is transmitted twice; if the same address is not received both times, data corruption is assumed, and the pager is not alerted. In the Mark IV, V and VI paging formats, error detection is limited to parity bits and the repeat of information. The more sophisticated error detection and correction codes transmitted as part of many other digital transmission formats are not used.

Swedish MBS Format

The Swedish MBS paging format supports paging over large geographical areas without the necessity of having to allocate the same frequency throughout the network. The format is transmitted along with the main signals of a radio station within a segment of the transmission known as the subcarrier. These subcarrier signals are part of every FM radio and television transmission and normally are removed and ignored by receivers. The original MBS format was designed to support tone-only paging and numeric display paging of up to 12 digits. Later modifications to the format have extended it to support longer numeric messages as well as alphanumeric display.

The Swedish MBS digital encoding format initially was developed for use in the public radio paging system operated by the Swedish Telecommunications Administration. This paging format is designed to be transmitted over FM radio station subcarriers. Pagers utilizing this format are capable of scanning the FM radio band and will lock into special signals that are continually transmitted to indicate that paging data is being sent over a particular radio frequency. When a pager first is turned on, it can take up to 30 seconds to locate an FM station that is transmitting the paging signals.

The MBS format is transmitted at 1187.5 bits per second. The six-digit pager address allows up to one million pagers to be alerted within one paging network. An additional two-digit code allows multiple networks to exist at one time. Each network must be given a unique two-digit identification number that is transmitted continually along with page alert signals. When there are no page alerts to transmit, this network identification code continues to transmit. When a pager is first turned on or if it moves out of range of a particular FM radio station, the pager will scan at a 57,000 cycles per second (kilohertz) signal that is continually transmitted and will look for the network identification code that is encoded within that transmission. When the correct network code is detected, the pager will lock on to that radio station and look for its unique pager address.

The paging format is oriented around sequential transmissions of 26 bits. These transmissions contain 16 bits of information and 10 bits of error detection and correction coding. The six-digit pager address is expressed as six four-bit binary digits, thereby requiring a 52-bit transmission; a tone-only page can be transmitted in 44 milliseconds. For numeric or alphanumeric pagers, the paging data immediately follows the pager address in 26-bit blocks. Four numeric digits can be transmitted within the 16 data bits contained in each transmission block. Blocks containing message data do not contain the network identification code that is part of the address block. The original paging format specified that no more than 12 digits (three data blocks) could follow a pager address because the pagers themselves expect the network code to appear within four data blocks. Remember, pagers scanning for the correct frequency are looking for this code in order to lock into the channel. In the expanded MBS that supports longer messages, mechanisms have been provided to have this network code appear during the transmission of long messages.

In order to provide for battery conservation, all MBS pagers are grouped into one of 100 groups based on the first two digits of the pager address. When a pager is fully powered, it looks for its group number to be transmitted. Once found, it looks for its unique four-digit address within that group. The paging terminal must batch all pages according to its group number. When there are no more pages for a specific group, the pager powers down for 32.707 seconds. During this battery-conservation period, the receiver will not detect pages. For maximum battery life, the paging system must be able to send new pages to this group as soon as possible after this 32.7-second period. If there are no pages for a group, a dummy number must be sent so that the pagers will return to their low-power mode. This paging format currently is used by a Cue Nationwide Paging in the United States.

Radio Data System (RDS) Format

The Radio Data System (RDS) format also was developed by the Swedish Telecommunications Administration. Like the Swedish MBS format, it is transmitted via FM subcarrier. However, the RDS system not only provides tone only, numeric and alphanumeric paging services, but provides many other non-paging radio services. The RDS format is a general radio receiver format that allows for a variety of different services including the ability for traffic information to be continually updated on displays within automobiles or causing an in-car cassette tape player to stop temporarily and tune the car radio to a traffic or weather report.

With RDS, if you like a particular type of radio program format (jazz, country, talk or classical, for example), a button can be pressed that scans only for strong stations that currently are playing your favorite format. This is accomplished by forwarding RDS information within the subcarrier of the FM radio station that contains information regarding the current type of programming ongoing within the voice portion of the radio channel. During a talk show, for example, a coded signal is sent on the subcarrier indicating what type of topic is being discussed (politics, entertainment, news, weather)but during a music program, other codes are sent indicating what type of music is playing (country, new age, blues, rock).

The goal of the designers of the RDS system was to have the format adopted throughout Europe. The format is being used for nationwide paging within France, in the Caribbean and in many other locations around the world.

Paging within the RDS format is designed to handle a ten-digit numeric display, 18 digit numeric display and 80-character alphanumeric display messages. Like MBS, the RDS system operates at 1187.5 bits per second and is based on a 26-bit word consisting of 16 data bits and 10 error detection and correction coding bits. The error code allows correct information to be received even if an error burst of five bits occurs within the 26 bit block. Four blocks of 26 bits are interpreted together as a 104-bit signal referred to as a “group.” Depending on the type of information contained within the group, a different “group type” code is defined and transmitted within that group. Because different types of services can reside simultaneously within a RDS network, different group-type codes will be transmitted sequentially. If more than 104 bits are required to completely send the page alert and message data when a page alert is transmitted to a pager, there is no requirement that the next segment of the transmission be sent in the next group.

A different group type used to send information for another data service may appear during the transmission of paging data. In other words, in the RDS format, information for different services are multiplexed into a single transmission stream; for example,paging is known as Group Type 7A.

Group Type 1A is transmitted at least once per second. This group contains special information that is used to keep receivers synchronized and locked into the channel, and provides encoded timing signals that are used to provide pager battery-life conservation. These timing signals break each minute up into 10 intervals. The last digit of the pager address determines in which interval the pager alert signal will be transmitted. A pager can interpret the timing signals that are transmitted each second and determine how long to stay in a battery-saving mode before it needs to increase power to detect a possible page alert. Because of encoding format rules, a pager never needs to power up for more than 18 seconds of each minute and, in most cases, is powered off much more quickly because it “knows” that no pagers are being alerted within its timing interval.

European Radio Message Standard (ERMES) Format

The European Radio Message Standard (ERMES) is a standard that was developed by a subcommittee of the European Telecommunications Standards Institute (ETSI) responsible for all communication standards throughout that continent. The committee was charged with developing a European-wide radio paging network. Although each part of the network will be operated by carriers within each country, subscribers can be alerted on their pagers regardless of where they are located within the network. Likewise, callers may call from anywhere in the network and use the same input protocol to alert any subscriber anywhere in the network.

When fully implemented, ERMES is expected to operate in more than 16 European countries with a combined population exceeding 320 million. In January 1990, 26 operators from 16 countries signed a Memorandum of Understanding (MOU), indicating their agreement to create a service based on this standard. In support, all signers of the MOU have agreed to allocate the frequency range 169.4 – 169.8 Mhz to this new service.

Because ERMES would involve system operators, pager manufacturers, paging terminal manufacturers and transmitter equipment manufacturers together, it was decided that an entirely new standard would be created. This would avoid giving any individual entity a bigger head start than any other in developing ERMES-compatible equipment. The standard is comprehensive in that it encompasses various analog and digital telephone input protocols; data network input protocols; protocols for moving tone-only, numeric, alphanumeric and data messages to paging terminals, protocols for encoding information to the pager; protocols for moving information to the transmitter equipment. This section will be limited to a discussion of the ERMES pager encoding format.

The ERMES digital encoding format supports tone-only, numeric and alphanumeric paging in addition to data transfer capabilities. The format operates at 6250 bits per second. Like the MBS and RDS formats, pagers operate on multiple frequencies, scanning for the best frequency for optimum reception. Scanning pagers allow for operations at different frequencies at different points in the network. The specification denotes 16 frequencies over which pagers are to operate.

The paging format uses a modulation mechanism known as “Four Level Pulse Amplitude Modulated FM.” In this mechanism, two binary bits of information are transmitted simultaneously through the transmission of one of four signaling frequencies. One set of frequencies is interpreted as the two binary bits “00,” another as “01,” another as “10,” and the final frequency as “11.” Therefore, with frequency transitions at the rate of 3,125 per second, 6,250 bits of information may be transferred.

Under the ERMES protocol, every hour is broken up into 60 cycles, each one minute induration (cycles 0 – 59). Each cycle is divided into five equal subsequences of 12 seconds each (subsequences 0 – 5). Finally, each 12-second period is divided into 16 separate batches (batches A – P). The batch number, subsequence number and cycle number of each transmission is encoded into the system information partition of each batch. Over the 16 different frequencies that support the ERMES format, the first batch to be sent in each subsequence is a different batch number. Batch A is the first batch sent on Channel 1, the sixteenth batch on Channel 2, the second batch on Channel 3, the fifteenth batch on Channel 4, etc. This methodology allows a pager to step through paging frequency channels without losing any messages. For battery-conservation purposes, pagers are designed to be activated starting at one of the 16 batches. Furthermore, a pager can be programmed to be paged only in particular subsequences or even in particular cycles.

Each pager is specified by a 35-bit address known as the Radio Identity Code (RIC). This unique address consists of 13 bits that are specific to the “home system,” where the subscriber database information is maintained, and a 22-bit local address for the specific pager. This large address field will accommodate a global address scheme to support hundreds of millions of pagers.

A batch contains separation partitions of information known as the synchronization partition, system information partition, the address partition and the message partition. Within each batch, the address partition contains the first 18 bits (the initial address) of the unique pager number ordered in descending order. This technique allows a pager quickly to determine if its unique address is not part of this batch so that it may return to battery-saving mode. All pagers whose addresses are larger than the initial address can return immediately to battery-saver mode. Messages are transmitted directly after the address partition.

Each message is preceded by a 36-bit message header. This header contains the 22 bit local pager address, a message number and additional information about the message. The message number is an important feature of ERMES pagers; if the pager finds that the next message number received is not the next number expected, then the pager will alert the subscriber that a message has been missed. The ERMES system provides a feature where a subscriber may call in to retrieve any lost messages. Note that if this pager is part of a group of pagers being alerted at one time, a special indicator is set in the header to indicate that the sequence number is not being sent and should not be checked.

Some of the additional information that is contained in the message header indicates if this is a tone-only, numeric, alphanumeric or data page; indicates which of eight different beep patterns should be used; indicates if this is a priority page; defines which of many different character sets should be used to display the message; and several other functions. The format also allows for the remote programming of pager parameters over the air as well as the temporary creation of pager groups.

The system partition, address partition and message partition of each batch consists of bit sequences that are some multiple of 18 bits. Associated with each 18 bits of data is a 12-bit error detection and correction code; together they create a 30-bit “codeword.” With the 12-bit code added, any two errors in the 30-bit codeword can be corrected, and any three errors may be detected by the pager.

For higher reception probability, a method known as “codeword interleaving” is used within the message partition of the batch. Every nine codewords are grouped together and are referred to as a “codeblock.” Rather than transmit the bits in codeword order – Codeword 1 to Codeword 9 – the bits are transmitted starting from bit 29 (the most significant bit) of Codeword 1, to bit 29 of Codeword 2, to bit 29 of Codeword 3 and soon until bit 29 of Codeword 9. Then transmission continues from bit 28 of Codeword 1, to bit 28 of Codeword 2 and so on. Treating the nine codewords as nine rows of 30 columns and transmitting the information by column rather than by row reduces the probability that a radio-burst error will affect the error-correcting capabilities of the protocol. If a number of bits in a row are corrupted, the error is spread across many different codewords, each of which has the ability to correct any two-bit error.

Hexadecimal Sequential Code (HSC) Format
The Hexadecimal Sequential Code (HSC) format, introduced in 1979, is the only analog paging format that was designed to provide numeric display paging services. The HSC format is a way of providing display paging to carriers who have analog transmitter equipment not capable of transmitting the signals associated with digital paging formats. HSC supports tone-only, numeric display, voice paging and a combination of numeric display with voice.

HSC is a variation of the 5/6 tone format. It continues to use the ten tones that represent digits 0 – 9, the “R” tone to repeat the last digit and the “X” tone used to signal a second beep pattern. Four additional tones (one being NO TONE, a frequency of zero) are defined, resulting in 16 different tones; these tones are referred to as the 0 – 9 and A – F tones. (The word Hexadecimal in HSC comes from the 16 tones that are used.)

Careful design of the HSC encoding format ensures that 5/6 tone pagers operating on the same frequency are not paged accidentally when HSC signals are transmitted. Three of the tones in HSC, “A,” “B,” and “D,” appear as “tone gaps” in normal 5/6 tone paging and cause those pagers to reset their decoders to ignoring the tone sequence received thus far. By partitioning a transmitted sequence with these tones, normal 5/6 tone pagers will not be alerted accidentally. If an A, B or D tone appears after any four tones, 5/6 tone pagers will not recognize a five-tone sequence that might match its pager address. If a telephone number is being transmitted, the tones 0 – 9 cause these digits to be displayed; the digit “C” causes a hyphen to be displayed; and the codes A, Band D are not displayed. After four sequential digits of a transmitted telephone number,the D tone is sent to avoid 5/6 tone pager false alerts. The pager display will not be affected.

Five combinations of HSC tones are used to activate special features of HSC pagers. These codes — BD, CB, CD, DB and DC — are ignored by 5/6 tone pagers because they appear as tone gaps. Each of these codes is followed by a numeric digit to further define a feature code; in this way, many different pager capabilities may be activated. Some of these codes are used to:

  • Display numeric information on the pager
  • Cause special visual symbols, such as an image of a small telephone(meaning extension number) to appear
  • Cause internal switches within a receiver to be open or closed, thereby controlling external devices
  • Indicate a priority page, allowing page alerts even if the pager is set to silent operation
  • Power up the pager’s speaker to listen to a voice page
  • Activate features within the pager, such as its battery-saver option.

A combination of codes allow a display message to be received as well as a voice to be heard, a feature unique to HSC receivers.

Morse Code

In the United States, every carrier who is allocated the use of a frequency is assigned a unique station identification code. The Federal Communications Commission (FCC) requires that this code be transmitted at least once an hour. The format of the transmission is not specified; it could be a voice message giving the call sign of the station, but more often, the information is transmitted as a Morse Code signal. This code, originally developed to send messages over telegraph wires, consists of short (dot) and long (dash) tones that, in combination, represent letters and numbers.

The coded signal is created in a variety of ways. In analog systems, a tone of any frequency can be selected and used to send the dot and dash signals. Many all digital systems do not have the ability to transmit analog tones, therefore, short and long bursts of binary “1s” and “0s” are sent. Regardless of the mechanism used to generate the sound of a dot and a dash, the station identification is transmitted. Typically, in the United States, a radio station code is specified as a three-letter and three-number code, such as KQX143. Because of FCC requirements to transmit station information even during periods of heavy paging transmission, Morse-Coded station identification often is treated within a paging terminal as a high-priority page that is sent once per hour.

Letters and numbers are encoded in Morse Code as follows:

 

1

° – – – –

A

° –

K

- ° –

U

° ° –

2

° ° – – –

B

- ° ° °

L

° – ° °

V

° ° ° –

3

° ° ° – –

C

- ° – °

M

- –

W

° – –

4

° ° ° ° –

D

- ° °

N

- °

X

- ° ° –

5

° ° ° ° °

E

°

O

- – –

Y

- ° – –

6

- ° ° ° °

F

° ° – °

P

° – – °

Z

- – ° °

7

- – ° ° °

G

- – °

Q

- – ° –

 

 

8

- – – ° °

H

° ° ° °

R

° – °

 

 

9

- – – – °

I

° °

S

° ° °

 

 

0

- – – – –

J

° – – –

T

-

 

 


FLEXTM Format
Motorola has developed the FLEXTM family of high-speed transport protocols which is being positioned as a standard for the wireless communications industry. While Motorola owns and controls this family of protocols, Motorola is licensing the protocols to enable their acceptance globally. The first family member is the FLEXTM high speed one-way paging protocol. It is capable of operating at data speeds of 1600, 3200 or 6400 bits per second. The format supports the delivery of tone only, numeric, alphanumeric and binary data to remote receivers. It sends paging data in fixed size batches which utilize a data interleaving scheme similar to that of the Motorola Golay format (described briefly as part of the ERMES discussion). This interleaving provides for a high degree of burst error protection. Error protection is further enhanced by imbedded checksum information within the transmitted data. A number of consecutive interleaved blocks are grouped together into frames. Sequences of frames are repeated cyclically each hour.

The protocol is time synchronized, transmitting frames at very specific time intervals. The first frame typically starts on the hour. Pagers may be set up to normally expect its pages to arrive during certain transmission frames, yet, under system control operate to receive pages in frames which occur more often. This may be used when a channel is lightly loaded in order to send several pages at one time rather than spreading them over a longer period of time. It also allows FLEXTM to be introduced into an existing paging channel minimizing the amount of airtime used by FLEXTM until traffic volumes dictate additional airtime. When pagers are operating to only expect transmissions to occur in their normal frames, battery life may be extended at the expense of a slightly longer message latency.

At its highest operating speed, the protocol simultaneously delivers 4 time multiplexed data streams at a time, allowing each pager to continue operation at a low speed (1600 BPS) while the channel carries 6400 BPS. The paging format is capable of addressing more than 1 billion device addresses. Frames are created in such a way as to minimize the time it takes a pager to determine if the frame contains a message for its address. This further improves the battery life of FLEXTM based pagers.

FLEXTM provides a range of operating modes which allow the paging terminal a great degree of flexibility in optimally transmitting pages on queue based upon traffic loading conditions. Long messages may be segmented into shorter pieces and reassembled by the receiver. This allows shorter messages to be transmitted between the segments of larger messages. Other features allow certain page requests to be replaced by shorter transmission sequences thereby allowing more pages to be delivered in a given period of time.

APOC Format
The Advanced Paging Operations Code (APOC) is a proprietary pager protocol of Philips Paging. The format has been designed to allow POCSAG paging systems to gracefully introduce new paging features and capabilities in an existing paging network. These enhancements include extra channel capacity, extended battery economy and additional network features. It has been designed to coexist with standard POCSAG transmissions.

Battery life extensions are accomplished by grouping APOC pager transmissions into cycles which traverse many individual POCSAG batches. More than a tenfold increase in battery life may be accomplished by allowing the pager to remain in a low power mode more often than that achieved in standard POCSAG. Of course, battery life is extended at the cost of a small increase in the latency of a page transmission.

The APOC format is particularly suitable for alphanumeric paging. It incorporates a built in dictionary held in each pager and the transmission of short data sequences which reference this dictionary, in order to provide a considerable degree of message compression. This not only results in increased reliability in sending long textual messages, but effectively increases channel capacity by reducing the number of data bits required to send a message. APOC also addresses the efficiency of numeric page transmission by providing a mode of operation which allows numeric pages which do not contain any special characters such as spaces, hyphens and parenthesis, to be sent with, typically, a 20% increase in channel capacity. A 50% increase in capacity can be achieved for 7-digit numeric messages. Go to this link for the latest update on APOC and RAMP, courtesy of Philips Paging.

Under the APOC enhancements, mixed data transmission speeds may operate on a single channel. Standard APOC operates as a 1200 bit per second transmission, but, data codewords may be sent at 2400, 3200, 4800 or 6400 bits per second. This is accomplished by sending specialized POCSAG synchronization codewords at the 1200 bit per second rate, which indicate that in the period of a standard 1200 bit per second POCSAG batch, data will be transmitted at a specific data rate. In order to improve page reception reliability beyond that of standard POCSAG, APOC incorporates a codeword interleaving technique similar to ERMES to increase the error detection and correction capabilities of certain types of page transmissions, well above that of normal POCSAG pages.

APOC introduces the concept of an extended address field which increases pager addressing beyond the 2 million pager numbers of standard POCSAG. It also introduces a control field which provides for new paging capabilities. These new fields are used to provide such features as:

  • transmission of binary data
  • message sequence numbering
  • support for information services to broadcast data which may be received by pagers which subscribe to one or more of these services
  • creation of closed user groups
  • ability to simply convey the priority of the message alert and note if the paging network is holding a voice message which is tied to this page alert
  • ability to display a predefined canned message at the pager
  • various over-the-air programming features
  • switch to alternate character sets
  • transmission of local time of day data

The synchronization technique employed in APOC allows APOC pagers to recognize POCSAG transmissions allowing these receivers to roam between APOC and unmodified POCSAG networks.

Two Way Paging
The most recent pager technology advancement at the time of this writing, is in the introduction of two way paging technologies. Paging receivers equipped with battery efficient transmitters, are now capable of returning responses which are eventually returned to the paging control terminal. The control terminal in turn, can then forward a response to the originator of the page request through any means of communication supported by the paging terminal. This could include the sending of another page, a voice mail response, telephone dial out, fax delivery, forwarding of E-Mail, etc.

Various responses from receivers are possible, based upon the features of the pager and paging protocols utilized by the portable transceiver. Some possible pager responses could be:

  • Message received correctly
  • Message read by subscriber
  • Yes/No
  • Selection from a list of choices
  • Selection of a pre-defined canned response
  • A short message
  • A long message

Different devices could offer some or all of these responses. Some of these responses could cause a status update to be requested at the paging control terminal for caller pickup or could initiate the forwarding of a response to the caller.

Some of the two way protocols support autonomous registration. This is the sending of a special control packet from the pager when it is powered on or enters the coverage region of a paging network. In this way, the paging control system can determine if there are any waiting messages to send to the pager when it is first becomes known to the network. This can be further extended in a multi-city network to provide for automatic roaming capabilities.

For proper operation of a two way paging system, information sent to the pager must be tagged in such a way that the eventual response or responses sent from the receiver,can be associated with a particular message sent. The responses could come a considerable period of time after the message is originally transmitted. Pager protocols(encoding formats) either had to be expanded upon to convey additional information in support of two way paging or entirely new formats had to be developed. There are several competing two way paging technologies in existence today. Some of these two way paging protocols will be reviewed in this section.

Two way paging requires a network of radio receivers to interpret the transmissions from the pagers. It is possible for more than one receiver in such a network to detect a transmission from a single pager. A number of different components exist in a two way paging system to properly process paging responses and move them back to the paging control system which is to ultimately alert the message originator. It is the function of some of these components to address the duplicate response situation.

New protocols have been developed between each of the network components to properly convey response information from the pager to the central control terminal. The discussions in this section will be limited to some of the pager protocols in place and not the protocols used within the network components.

ReFLEXTM
ReFLEXTM is a Motorola designed two way advanced messaging FM protocol. The protocol defines the manner in which message and control data is sent to the paging and messaging receiver as well as the manner used to return the various types of responses from the receiver. Protocol flexibility allows receivers to transmit their responses on a different frequency than that over which the message was received. Further features permit ReFLEXTM operations over 25 KHz or 50 KHz wide channels, providing for higher data rates and customer capacity at the higher bandwidth. Proper system operation in each of these operating modes dictate that ReFLEXTM operate as a time synchronized protocol. The paging receivers utilize the same time base as well as information conveyed within the transmitted data stream to precisely time when a pager is to send its responses. The response time periods may be dynamically changed or assigned based upon the current loading conditions of the radio channel.

The ReFLEXTM protocol shares many attributes with the FLEXTM one way FLEXTM paging protocol and is able to be mixed on the same channel with the other FLEXTM type protocols. The outbound paging channels may operate at 1600, 3200 or 6400 bits per second although ReFLEXTM may also operate over multiple 6400 bit per second data streams if sufficient bandwidth is available. The same paging capabilities and page transmission features of FLEXTM, including segmentation of long messages and the ability to utilize alternate mechanisms to reduce the transmission time of certain messages, exist within ReFLEXTM. But the ReFLEXTM protocol introduces an array of specialized over-the-air commands to address the control of messaging unit responses.

Messaging units transmitted responses fall into two categories, solicited and unsolicited. The protocol dictates when unsolicited response are allowed to arrive. There are several types of unsolicited responses which may be sent. Some unsolicited responses could result in a subsequent solicited response. The outbound transmission equipment has complete control, through the ReFLEXTM protocol defined commands, to precisely schedule the transmission of certain responses which are pending in the messaging unit. The ReFLEXTM protocol provides a choice of multiple signaling speeds for response messages sent from the messaging unit, to allow the system structure to operate with the fewest number of receiver sites for a given traffic level. The ability to schedule location specific transmissions provides a reuse feature for the operating system allowing maximum utilization of the RF spectrum.

inFLEXionTM
Another member in the family of FLEXTM protocols is InFLEXionTM, Motorola’s advanced voice and data messaging protocol utilizing both FM and Linear modulation signaling methods. The FCC action to release 50 KHz wide Narrow Band PCS channels has allowed the inFLEXionTM technology to become available. The inFLEXionTM protocol allows for the creation of a voice and data messaging network with frequency reuse capabilities similar to that of cellular telephony. The protocol is based upon the ReFLEXTM protocol already discussed. It is also possible to operate completely in a simulcast mode. Other FLEXTM type protocols may be mixed on an InFLEXionTM based channel. InFLEXionTM based systems make specific use of the ReFLEXTM capability to request a messaging unit to respond to a location request, combined with directed transmission of pages within specific geographic areas. The messaging unit response enables the network control equipment to determine the specific geographic area in which the messaging unit is located. Using this response, a voice message may be sent to the nearest transmitter(s) to which the pager is currently located. The voice messaging over the 50 KHz channels features variable compression techniques allowing equal to or greater than 24 times the subscriber capacity of today’s 25 KHz channels. Simultaneously, other voice messages may be delivered on the same frequency to messaging units which are geographically separated from each other so that there will be no transmission interference. With InFLEXionTM Data signaling the throughput on the 50 KHz channel allows signaling of up to 112 KBPS. As in ReFLEXTM systems, the InFLEXionTM protocol provides a choice of multiple inbound signaling speeds to allow the system structure to operate with the fewest number of receiver sites for a given traffic level.

NexNetTM
NexNetTM is a proprietary two way paging system designed by Nexus Telecommunications Ltd. of Israel. It utilizes spread spectrum technology integrated into their paging receivers to transmit response messages. In its initial implementation, messages are forwarded to pagers through the utilization of the POCSAG protocol. The additional messaging information required for time synchronization of the transmitted messages with the two way pager responses sent at a later time, as well as the transmission of two way paging control data, is imbedded within standard POCSAG output data. NexNet outbound data in support of two way paging is sent in such a way as to be totally transparent to normal POCSAG transmissions so that two way paging may coexist in any preexisting one way paging system.

The Nexus two way paging device, known as the TwagerTM, sends responses formatted according to the NexNet “uplink” protocol specification. In the Spread Spectrum technique, the data is transmitted over a range of different frequencies and is detected by receiving equipment located throughout the coverage region. Each Twager utilizes different sets of frequency combinations (frequency hops)when transmitting their data. Complete response messages may be recovered at receivers even though some portions of the response message may have been corrupted. This is because a message segment which is corrupted because of interference from other transmissions or by a simultaneous transmission from another Twager at one or more frequencies, has a high probability of being properly received at other frequencies over which this segment is transmitted.

In order to simplify the reception of the spread spectrum frequency hopped signals, the transmissions from the Twagers are required to synchronize to a precise clock. This precise time synchronization is achieved through the transmission of precision timing data which is imbedded in the POCSAG output stream. But, this is accomplished in a manner which permits this data to be overlaid into existing paging networks without the need to add any specialized transmission equipment.

New Code Formats From the PCIA High Speed Paging Committee
Since paging began, new paging formats have been developed to incorporate new transmission technologies and to bring new features to the subscribers. New transmission techniques may result in higher transmission speeds and/or higher reliability in the receipt of paging data or a lower cost to transmit information over larger geographical areas. New transmission formats may result in sending more information with fewer data bits, better battery saving capabilities to prolong battery life, or to provide services and features that go beyond that of traditional paging. For example, a variation of the POCSAG format fully compatible with normal POCSAG pages, allows for the forwarding of spreadsheets, computer data and even computer programs over paging channels for reception by laptop or palmtop computer devices. This technique, described by the TRT protocol specification as part of the TDP protocol, extended the POCSAG format for the transmission of data, a capability which was not part of the original specification.


           

E. Keunggulan Penggunaan Pager

kelebihan dari alat komunikasi peger ini adalah bahwa pengirim pesan tidak harus memiliki pesawat pager dalam mengirimkan pesan, namun pengirim pesan cukup menghubungi operator pager via telephone.

 Pager merupakan media yang relatif lebih murah dalam menggunakannya dan juga cepat dalam penyampaian informasinya. perangkat pager ini dulunya diminati disebabkan oleh  keunggulannya  yang mampu menerima informasi dimana saja tergantung posisi si pembawa pager (mobile), jadi pager  menjadi alat pelengkap bagi media telepon,  yang  saat itu tidak bisa dibawa kemana-mana.

Disamping itu, pager juga memiliki keuntungan dari segi privasinya dibandingkan telephone selular, karena sebuah one – way Pager adalah hanya sebagai penerima pasive ( pesan dikirim , tanpa informasi balikkan ke base station ), jadi  base station yang menjadi perantara tidak dapat meninggal informasi secara spesifik, yang diketahui oleh banyak orang.

            Alasan keuntungan memakai   pager, yang lain adalah sebuah alasan yang terkesan kurang bertanggung jawab, yaitu pager memungkinkan  Kita untuk  bisa punya alasan untuk tidak mengkontak balik ke orang yang mengirim pesan dengan alasan, tidak  ada telepon umum untuk balas atau menelpon kembali. Jadi, walaupun  dikirim pesan ,kita tetap punya alasan yang cukup bagus untuk memutus komunikasinya..

 F. Kelemahan Penggunaan Pager


          Proses cara kerja pager yang rumit, menciptakan ketidak efektifan dalam melakukan sebuah komunikasi, terlebih lagi adanya keterbatasan dalam penyampaian pesan sehingga tidak bisa digunakan untuk pesan yang kompleks.

 

Selain rumit dalam hal mengirimkan pesan, kekurangan lain dari alat pager ini adalah pesan yang disampaikan sangat terbatas dan tidak bisa digunakan untuk menyampaikan pesan yang kompleks, dan juga kita cenderung hanya ingin mengetahui dimana teman kita berada atau hal hal yang dianggap penting, jarang sekali alat ini dipaki untuk Curhat bersama teman apalagi lewat orang ketiga yaitu mediator provider yang pasti akan mengetahui semua curhatan kita.

              Salah satu bentuk kerumitan dalam penggunaan pager terlihat dari sebuah Pesan yang  ingin dikirim ke pager harus di informasikan terlebih dahulu dari setiap paging transmitter pada pager’s service area.message , sehingga besar kemungkinan  jika  sebuah pager memiliki nation icsercive, sebuah pesan yang dikirim  dapat tertangkap atau diiterupsi oleh pihak – pihak yang tidak diinginkan .

 

G. Alasan Pager Ditinggalkan Oleh Sebagian Masyarakat

 

pager, hanya bertahan seumur jagung di masyarakat  . Padahal modal yang dikeluarkan untuk pengadaan pager ini sangatlah besar. Bahkan di Amerika serikat sendiri terdapat perusahaan besar seperti MCI-WorldCom yang membeli Skytel (provider pager dua arah) dengan sebuah pengharapan bahwa pager akan booming  sehingga menghasilkan pundi-pundi uang bagi mereka. Tetapi kenyataan berkata lain.

            pager telah kehilangan peminatnya karena  adanya handphone yang lebih banyak memberikan keunggulan bagi para pemakainya. Kemunculan Handphone membuat pager terpuruk, dengan cepat menjadi barang kadaluwarsa. HandPhone menjadi  sangat populer kepraktisannya. Dimana Operatornya bukan manusia lagi, namun  sistem. Disamping itu faktor fungsi dan efisiensi penggunaan pada perangkat handphone, mampu saling merespon pesan oleh kedua belah pihak secara langsung, pribadi dan tanpa perantara. Sedangkan pada kenyataannya pager yang hanya bisa menerima pesan dan membalasnya lewat pesan juga tanpa bisa melakukan komunikasi verbal (telepon) membuatnya perlahan – lahan  tersingkir dan akhirnya tenggelam dan digantikan oleh Handphone pada awal tahun 1990 dalam kancah bisnis komunikasi.

 Penggunaan ponsel sendiri bagi beberapa kalangan di Indonesia sudah sebagai kebutuhan primer, yang otamatis dianggap lebih berfungsi untuk menggantikan posisi pager. Tidak sedikit orang termasuk penulis yang merasa lebih baik ketinggalan dompet di rumah daripada ketinggalan ponsel. Pada taraf ini, apa bila terjadi sesuatu pada ponsel sudah merupakan sedikit bencana bagi pemiliknya.

Latar belakang mengapa ponsel begitu penting dalam kehidupan sosial saat ini hingga mampu menggeser posisi pager, cukup beragam, salah satunya adalah karena ponsel merupakan media informasi dan telekomunikasi yang relatif murah, cepat dan up-to-date serta sifatnya yang dua arah, artinya dengan adanya ponsel, informasi diperoleh si pengguna secara lebih lengkap, lebih informatif dan lebih aktual. coba kita bandingkan dengan penggunaan pager yang pernah booming kira-kira dua belas tahun lalu.

Demikian dapat dimaklumi  unsur terpenting dari keberadaan suatu ponsel , yang menggeser pager adalah informasi yang disalurkan melalui media ponsel itu sendiri. Informasi dalam hal ini memiliki cakupan yang luas termasuk tetapi tidak terbatas informasi berupa suara, gambar, teks, video, dan data. Keberadaan ponsel sebagai media informasi yang penggunaannya semakin kompleks serta memiliki cakupan luas dalam kehidupan masyarakat ternyata juga dimaanfaatkan sebagai media promosi yang efektif bagi pelaku usaha untuk mempromosikan produk barang atau jasanya, sedangkan dahulu pager tidak bisa melakukan hal ini.

Terlebih lagi posel juga mampu menggeser posisi pager, yang dulu sempat menjadi booming karena ponsel menyediakan layanan SMS, yang dapat mengirim dan menerima pesan , dimana SMS ini pertama kali diuji coba pada Desember 1992. Pesan itu dikirim dari sebuah PC ke sebuah telepon seluler dalam jaringan GSM milik operator seluler Vodafone di Inggris. Tak ada yang menyangka bahwa hal itu akan menjadi dasar dari satu aplikasi terpenting komunikasi nirkabel. Nyatanya, selama 13 tahun kemudian, pemanfaatan short messaging service terus melambung, dan pemakaian pager khusunya di Indonesia mengalami penerunan dari waktu – ke waktu.

 

H. Strategi Operator Pager yang Ingin Kembali Eksis di Indonesia

            Setelah lama tidak terdengar gaungnya akibat penetrasi dari telephone seluler, operator radio panggil (pager) kini berusaha tampil lagi ke permukaan. Apa saja kiat-kiat operator pager untuk bisa kembali?

            OPERATOR pager kini mulai berbenah demi menggaet kembali konsumennya yang sempat lepas beralih ke ponsel GSM dan CDMA. Pager yang pernah merajai pasar sekitar 1989-1998 silam itu, kemudian tenggelam di tengah derasnya arus ponsel yang memiliki fitur tidak berbeda seperti fasilitas pager, yaitu SMS. Namun, hal itu tidak mematahkan langkah operator pager yang masih beroperasi. Bahkan, mereka yakin dalam jangka waktu dua tahun ke depan, pager akan kembali booming. Prediksi ini didasari jumlah pengguna pager yang mulai meningkat dalam beberapa waktu terakhir.

            Direktur Operasional Starko Surabaya, Mochammad Aqib, menargetkan hingga akhir 2005, Starko bisa menambah 30 persen pelanggan baru lagi di Kota Pahlawan. Aqib mengenang betapa periode 1996-1998 mereka berjaya di pasaran. “Pada saat itu, jumlah pelanggan kami mencapai 28 ribu orang,” kenang Aqib. Namun, ketika memasuki krisis ekonomi, dan seiring dengan berkembangnya teknologi seluler, jumlah pelanggan turun drastis hingga menjadi ratusan orang saja. Tetapi, tren mulai berubah begitu memasuki awal 2000, yang ditandai dengan semakin meningkatnya pelanggan.

            Memasuki 2007 hingga 2008, dia memprediksi pelanggan pager akan mengalami peningkatan secara signifikan, sejalan dengan peningkatan layanan yang diberikan. Memang, diakuinya, saat ini radio panggil kalah bersaing dengan teknologi telepon seluler. “Tetapi dengan layanan lebih yang kami berikan, seperti info harga saham, indeks BEJ, nilai tukar mata uang, dan perkembangan harga emas yang tiap hari dikirim ke pelanggan, kami yakin minat masyarakat akan semakin tinggi.”

            Menurut Aqib, pager memiliki kelebihan jika dibandingkan dengan teknologi SMS. Antara lain satu informasi yang disampaikan ke operator, bisa dikirim ke lebih dari tiga pesawat sekaligus. “Sementara SMS, kita harus mengeluarkan biaya sebanyak SMS yang kita kirim,” katanya.

            Kelebihan ini diperkirakan akan diminati masyarakat dua hingga tiga tahun mendatang. “Tarif SMS akan terus mengalami kenaikan, sedangkan biaya berlangganan pager dalam dua tiga tahun mendatang masih stabil,” cetusnya. Per hari, imbuh dia, Starko mampu mengirim lebih dari 6.000 pesan ke semua pelanggannya di Surabaya. Saat ini, konsumen Starko masih didominasi korporat sebesar 70 persen dan 30 persen individual. Mayoritas konsumen pager saat ini adalah rumah sakit, perusahaan pengangkutan, hingga pialang saham.
“Beberapa RS di Surabaya saat ini masih menjadi pelanggan loyal kami,” akunya. Selain kalangan kedokteran, ada beberapa hotel yang menjadi pelanggan Starko, namun sistimnya berbeda. Perbedaaannya adalah, hotel membeli peralatan radio panggil dari Starko untuk diterapkan di hotel itu guna memudahkan komunikasi karyawannya. Karena mereka tinggal mengirim pesan tanpa melalui operator. “Fasilitas ini kami namakan in house paging.”

            Selain pelanggan hotel dan kalangan kedokteran, pelanggan Starko juga terdiri dari beberapa perusahaan ekspedisi juga masih setia menggunakan jasa pager. Dengan biaya berlangganan Starko yang cukup bervariasi mulai Rp 720 ribu yang sudah termasuk pesawat dan biaya berlanggaan selama tiga bulan, Starko optimistis pelangan mereka bertambah banyak.

             senada juga dirasakan PT Duta Pertiwi Santosa (pemilik brand Starpage). Branch Manager PT Duta Pertiwi Santosa Surabaya, Mien Chen, mengatakan inovasi layanan yang belum bisa didapatkan dari ponsel berbasis GSM dan CDMA diyakini bisa meraih pasar yang sempat hilang. Starpage melengkapi layanannya dengan info valas, pergerakan saham di BEJ (Bursa Efek Jakarta), bursa berjangka, sampai berita pertandingan sepak bola. “Semoga kejayaan pager akan kembali lagi,” tandasnya.

 

I. Penggunaan Pager Di ABAD 21

Berikut dibawah ini kita lihat beberapa bentuk pager

A Skyper pager that is in use for HAM Radio

A Skyper pager yang digunakan untuk HAM Radio.

 

 

A pager that is in use for emergency services

pager yang digunakan untuk layanan gawat darurat.

 

A mid '90s   opaque black Avont pager model

A mid ’90s opaque black Avont pager model

Pagers saat ini memang masih digunakan , namun penggunanya tidak sebanyak pada tahun 90-an, pager pada masa abad 21 ini digunakan, dimana mobile phone secara khusus tidak dapat  menjangkau atau menghubungi pengguna mobil phone lainnya , dan pager juga digunakan di beberapa tempat, dimana operasi radio transmitter yang terdapat pada mobile phone mengalami permasalahan atau hamabatan. Sebagai salah satu contoh adalah komplek rumah sakit , dimana  jaringan seluler sering sibuk atau  nonexistent, pada kasus seperti ini radio transmitters menyarankan untuk turut campur tangan dengan peralatan kesehatan yang sensitive dan dimana ada  sebuah kebutuhan jaminan yang besar untuk sebuah waktu pemesanan sebuah pesan.  

Beberapa lingkungan , biasanya memanfaatkan pager untuk :

  • Pagers remain digunakan untuk pemberitahuan info darurat kepada anggota   emergency . sebagai contoh, mereka yang memanfaatka fungsi ini adalah lifeboat men dan retained firefighters.
  • Pagers  , kebanyakan dibawa oleh staff yang bekerja dibidang kesehatan atau paramedis , ini berarti pager mengizinkan mereka untuk mengetahui kondisi gawat darurat si- pasien.
  • Pagers. Juga secara luas diguanakan dalam dunia IT, khususnya dalam kasus, diamana  seorang teknisi tidak dapat mengandalkan atau tergantung pada sistem telephone selular sistem. Sebagai contoh, misalnya pada sebuah perusahaan teleephone selular, terjadi gangguan layanan pada jaringan celluler, ini berarti tidak munkin telephone celluler untuk memberitahukan kepada seorang teknisi, yang tidak bisa dihubungi karena berada diluar jaringan. Oleh karena itu, diperusahaan seperti ini , teknisi biasanya dilengkapi dengan pager yang menggunakan telco’s mobile network, untuk mendapatkan keyakinan pada kasus gawat darurat.

Sebagai tambahan , beberapa sisitem control irigasi dan rambu lalu lintas sekarang ada yang menggunakan pesan via paging network untuk mengontrolnya. Persoalan perhatian energy di United States and dua Negara lainnya, 2Way paging networks menjadi digunakan untuk kekuatan perusahan dalam aktiviatas meter reading and kontrol.

 Kebiasaan lainnya menggunakan  sebuah teknologi pager kuno “ tone pager” dipenggunaan saat ini disebut dengan pager. dalam  Industri yang terkadang memenage banyak orang, hal tersebut memungkinkan kustumer untuk bersantai  di taman atau di bar , ketika menunggu untik pesanan mereka. Banyak restoran sekarang, menggunakan sebuah pendongkrak atau alat lainnya yang akan memberi tahu anda, saat meja anda siap dengan   flashing LED’s, buzzing dan vibrating.

 Berikut ini adalah beberapa jenis tipe pager yang hingga saat ini masih beredar di pasaran dunia, khususnya eropa :

Eagle Rager Pager

The Eagle Ranger numeric pager  menawarkan sejumlah feature menarik, termasuk kapasitas untuk 20 pesan numeric , kemampuan untuk store /lock 15 pesan dan 19 pilihan tanda bunyi , plus pilihan “getaran” dan “ silent/no silent” . dan sebagai tambahan, Eagle Ranger backs up all current and saved messages selama mengisi batere, menawarka message time stamping as well as 12 and 24 hour time format options.

 Daviscomm BR502

The BR 502 device menawarkan para profesional yang sangat sibuk sebuah kepercayaan dan jalan yang sangat menyakinkan untuk berhubungan dimanapun terhadap kolega mereka.  Dengan  kemudahan menggunakan  two-button design, scratch resistant lens, and removable belt clip. BR502 memberikan ketahanan dan kebutuhan fungsional untuk bertemu semua  numeric messaging.

 

motorola advisor elite pager The original Motorola Advisor Alphanumeric Elite pager. Pager ini telah dilengkapi sebuah tes yang telah teruji dan diperbaharui lagi lebih modern.

 

 

 

 

 

 

 

 

 

 

 

 

Kesimpulan

Jadi berdasarkan paparan materi diatas dapat kita simpulkan bahwa, pager ( radio panggil ) adalah salah satu media penerima pesan yang portable , yang terbentuk dari perpaduan dari perkembangan teknologi komunikasi dan teknologi informasi, dan merupakan simple personal telecommunication device yang berguna untuk menerima pesan singkat. Pada mulanya alat radio panggil ini bernama beeper, namun berubah ketika  motorolla menelurkan alat sejenis dan menamainya sebagai pager, pada mulanya pager ini dikembangkan untuk keperluan medis pada rumah sakit di negara negara eropa yaitu sebagai tanda dari pasien yang mengalami kondisi gawat darurat.

Pager memilliki bermacam macam jenis perkembangan    protokol yaitu diantaranya  one way pager protocol,two one format, five/six tone format,golay format, nec D 3 format, POCSAG format, Mark IV/V/VI Formats, Swedish MBS Format, Radio Data System (RDS) Format, European Radio Message Standard (ERMES) Format, Hexadecimal Sequential Code (HSC) Format ,morse code, FLEXTM Format,  APOC Format, Two Way Paging, ReFLEXTM,, inFLEXionTM, NexNetTM,, New Code Formats From the PCIA High Speed Paging Committee.

Dipandang dari segi kelebihannya pager hampir memiliki keunggulan mudah dibawa kemana mana, namun penggunaan pager ini tergolong rumit dibandingkan penggunaan posel dan dianggap kurang efektif oleh sebagian orang, oleh sebab itulah pager mulai kehilangan peminatnya termasuk di Indonesia, walaupun demikian ,ada suatu perusahaan yang berniat untuk membangkitkan kejayaan pager kembali. Tetapi perlu sedikit diketahui bahwa penggunaan pager sampai sekarang tetap dipergunakan pada rumah sakit dan beberapa Negara eropa, walaupun penggunanya tidak teralu banyak.


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3 thoughts on “PAGER

  1. wwwoooowwww,,,,,,,
    hebat nih buat kerjain PR aku. Ijin Copy yah!
    tapi mau tanya dong. cara kerja Pager itu kayak apa sih? bukan Cara pengoperasiannya loh??

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