701
Joined: Nov 26, 2002
Posts: > 500
From: Romania
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..and if any of u used it.I am curios how itworks,what r its features and generally,to know things about it.
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whizkidd
Joined: May 14, 2004
Posts: > 500
From: India
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This is what i found about PTT on wikipedia!
Hope it clears some of your doubts!
Push to talk, commonly abbreviated as PTT, is a method of conversing on half-duplex communication lines, including two-way radio, by pushing a button in order to send, allowing voice communication to be transmitted from you, and releasing to let voice communication be received.
One of the earliest mobile telephone protocols. It was the mobile equivalent of operator-assisted land telephone service. The protocol was as follows: The mobile telephone user pressed and held their PTT (Push-To-Talk) button for several seconds to get the mobile operator's attention. When they released PTT, an operator would reply (transmit on their channel) and ask them the number then wanted. The user would key up (PTT) and tell the operator the number they wished. The operator would dial and connect the land line, and the conversation would proceed. When there was no activity for awhile or the land line hung up, the operator could reuse the channel. This was used at least into the 1980's in Canada. This was replaced by MTS.
The term has come to be more commonly known as referring to a feature that is available on certain more recent mobile phone models. It allows the mobile phone, when in a special mode, to function as a digital two-way radio in push-to-talk operation (in a fashion similar to the "trunking" feature of newer commercial and public-safety two-way radios). Only one person at a time can talk, by pressing a PTT button, and one or several others can listen instantly. The service connects mobile phone users with each other within seconds. Currently, PTT users have to belong to the same mobile operator's (carrier's) network in order to talk to one another. PTT commonly does not use up the regular airtime minutes that are available for general voice calls, it uses the GPRS connection, on which the amount of data transmitted is billed, and not the minutes of conversation. Nextel Communications introduced mobile push to talk several years ago using iDEN and is currently the leader in this industry. iDEN technology is also used by SouthernLinc in the southeastern US, and as well as several other carriers worldwide.
Recently, Verizon Wireless and Sprint PCS in the United States, Advanced Info Service (AIS) in Thailand, Telstra in Australia and also Bell Mobility (known as 10-4 service) (CDMA) and Telus Mobility (known as MIKE) (iDEN) in Canada launched their push to talk services. And more operators all over the world have announced intentions to launch similar services.
Verizon is using for its service the Motorola v60p mobile phone, a modified version of the v60 that has the push to talk feature. Sprint PCS is using several models of Sanyo phones equipped with similar technology. Telstra and AIS are using the Nokia 5140 mobile phone and their GPRS networks.
The Motorola and Nokia versions of PTT are based on 2.5G packet-switched networks (CDMA by Motorola, GPRS by Nokia) and use SIP and RTP protocols. These particular versions of PTT are called "Push to Talk over Cellular", which is abbreviated "PoC". The Open Mobile Alliance is defining PoC as part of the IMS - IP Multimedia System - framework, and the standard is expected to be finalized in late 2004. A pre-standard version of PoC is also defined by the industry consortium made up of Motorola, Nokia, Ericsson, Siemens AG, AT&T Wireless, and Cingular Wireless with the aim of creating a commercial offering enabling inter-operability between vendors.
Push to Talk users are often criticized for using their phones in an inappropriate manner, which includes yelling into their phones during times and in places unsuited to having such a public conversation. Most Nextel iDEN phones have a feature that allows the user to have their PTT Conversation only over earpiece of the phone instead of over the loudspeaker.
T230 >> T610 >> Ngage QD >> N73 >> N85 >> Omnia HD >> And countless other review units |
Posted: 2005-08-28 13:28
