Dec 9, 2009 | Selangor Oje

Push to Talk

PTT PoC or Push to Talk over Cellular is a service option for a cellular phone network which permits users to use their phone as a walkie-talkie. A typical Push to Talk connection connects almost instantly. One significant advantage of PoC is that it allows a single person to reach an active talk group with a single button press; users no longer need to make several calls to coordinate with a group.

Push-to-talk cellular calls are half duplex communications — while one person transmits, the other(s) receive. Traditional mobile phone networks and devices utilize full-duplex communications, allowing customers to call other persons on a mobile or land-line network and be able to simultaneously talk and hear the other party. Such communications require a connection to be started by dialing a phone number and the other party answering the call, and the connection remains active until either party ends the call or the connection is dropped due to signal loss or a network outage.

Therefore, telephone communication protocol does not allow for casual and immediate transmissions to be sent to other parties on the network. Whereas telephone calls require the lengthy process of dialing, network switching and routing, call setup, and waiting for the other party to answer, a two-way radio has a much quicker protocol because of the immediacy of push to talk communication.

Full-duplex operation on mobile phone networks is made possible by using separate frequencies for transmission and reception. Mobile Push-to-Talk service, offered by some mobile carriers, adds functionality for individual half-duplex transmissions to be sent to another party on the system without needing an existing connection to be already established. Since the system is half-duplex, only one user can transmit by PTT at a time; the other party is unable to transmit until the transmitting user unkeys their PTT button. Currently, PTT service is supported only between parties on the same mobile carrier service, and users with different carriers will be unable to transmit to each other by PTT.

In addition to mobile handsets, the Push-to-Talk service might be complemented with fixed PC applications acting as PTT clients connected to the mobile operator via secured Internet links. A specialized type of PC Client is a dispatcher, similar to a PC client but designed for heavy load dispatching. That is, coordinating many issues typically caused when managing large fleets from a dispatch center. In Spain, Telefonica has launched PTT offering with focus on dispatch orientated group communications.

When used with GSM and CDMA networks, the PTT service commonly does not use up the regular airtime minutes that are available for general voice calls.

Nextel Communications introduced mobile push-to-talk in August 1993 using iDEN. The first system was turned on in Los Angeles with 134 sites and a capacity for 50,000 dispatch subscribers. The "MOTO Talk" feature by Nextel includes both on- and off-iDEN network walkie-talkie service for newer Motorola phone models. The off-iDEN-network handset-to-handset Direct-Talk feature works for a radius of up to six miles.

Tanggal 25hb November 2009 kunjungan dari rakan seSELANGOR..saudara kita yang mengelar diri beliau FAILANG...(kenapa ek..mungkin masa kerja selalu Hilangkan Fail kut)..telah disambut oleh rakan-rakan selangoroje yang diketuai oleh tuan tanah BODYGUARD dan anak-anak buahnyerr..Rakan-rakan selangor oje bersetuju dengan sebulat suara telah melabelkan beliau sebagai salah seorang antara ramai-ramai rakan oje sebagai seorang MAT JAMBU berdasarkan penampilan beliau dengan tangan selembut-lembutnya seperti dijaga dengan losyen baby oil..hehehehe..muka jambu siotttttttt..hehehehe..

Aksi,gaya seorang jejaka jambu dengan rokok sebatang...piiiiiiirahhhhhh..hehehe..

Saudara Failing badan jerr kecik bila makan melantak-lantak..uihhhh..bela hantu raya kut...cuba tengokk gelas-gelas kat meja depan beliau tuhh...perghhh

Turut hadir semasa perjumpaan dengan si MR.FAILANG wallawey dengan posing melantak-lantak sempat dirakam tanpa disedari oleh beliau..nie dinamakan posing tekan-tekan biru..biru..biru..

Turut serta dalam perjumpaan BILAL dan EJAL "The Reject Turbo" kelihatan EJAL sedang cuba menghantar setting reject kepada BILAL..kwang..kwang..kwang..

Ucapan penutup dan nasihat berguna dari Tuan Tanah BODYGUARD buat rakan baru selangoroje MR.FAILANG..antara teks ucapan.."Failang..engko kerja betul-betul,bila dah oje-oje nie engko jangan pulak asyik nak mengularrrr jerrr..hati-hati tuh..muka dahlah jambu nanti ramai pulak peminat susah pulak aku takde orang yang minat aku pulak..hampehhh...." sedutan teks ucapan dari BODYGUARD..hehehehe. Apa-apa hal Selangor oje mengalu-alu kedatangan RAKAN-RAKAN baru ke Selangor oje...persahabatan tanpa sempadan walau dimana jua anda berada.......