Mobile Multimedia Push toTalk
The Ribirth of technolgy gives a smooth path to innovative ideas. Among them Push to talk over cellular is an innovative idea implemented in third Generation technology. Push to talk is another service provided by 3G Networks. Push toTalk functions like a walkie-talkie, with an immediate response. The PTT communication is carried out in half-duplex mode. This service is for quick communication between end users. PoC enables the use of SIP as the signaling protocol over cellular data networks. The SIP protocol extensively works in the packet switched Network. (Vlasach, 2007)
Session Initiation Protocol (SIP):
Session Initiation Protocol (SIP) is an upgrade version of H.323 which is an application protocol used to create, modify and terminate the session with one participant. SIP is mainly used by VoIP to transfer the multimedia applications. It also supports both unicast and multicast streaming modes. SIP is an independent application protocol which can run on Transfer control protocol (TCP) and User-Datagram protocol (UDP).
(Rosenberg, 2002)
The main objective of SIP is to provide the signaling and call-setup for IP-based communications by making and tearing the call connection. The important characteristics of SIP are
• SIP is transport-independent since it can be used by UDP and TCP.
• SIP codes are in text-based allowing the user to read easily.
(Rosenberg, 2002)
The video conferencing technology uses the SIP protocol in IP based networks. The traditional network uses H.323.
Advantages of SIP:
• SIP is more streamlined protocol developed specially for IP telephony.
SIP can take control over the other protocols which cannot done by the H.323
• Call initiation and ending in SIP will be obtained by two communication tools helps to track the location of user.
• SIP can be easily updated like a HTML page.
(advantage of sip for VoIP, 2006
Establishment of Push-to-Talk communication:
SIP framework facilitates the PTT communication by providing end-to-end connection in all devices. SIP introduces a stack that is relevant in handling the wireless SIP User Agents (UAs).
SIP based PTT communication
Source: http://www.networkcomputing.com/gallery/2007/0625/0625ttb.jhtml
In normal standard SIP UA, the other UA communicate directly with the end devices which takes time and sometimes the connection will break which leads to loss of data and takes long time to get back to the normal state. But in PTT communication PoC server catches the status and settings of the wireless device. When the wireless network changes its status SIP updates the PoC server and when another device wants to connect the particular device, it checks with the PoC server and determines the connection to receive the data. This process makes faster connection between end users in PTT communication and also effectively prevents bandwidth use. (Vlasach, 2007)
Session Initiation Protocol (SIP):
Session Initiation Protocol (SIP) is an upgrade version of H.323 which is an application protocol used to create, modify and terminate the session with one participant. SIP is mainly used by VoIP to transfer the multimedia applications. It also supports both unicast and multicast streaming modes. SIP is an independent application protocol which can run on Transfer control protocol (TCP) and User-Datagram protocol (UDP).
(Rosenberg, 2002)
The main objective of SIP is to provide the signaling and call-setup for IP-based communications by making and tearing the call connection. The important characteristics of SIP are
• SIP is transport-independent since it can be used by UDP and TCP.
• SIP codes are in text-based allowing the user to read easily.
(Rosenberg, 2002)
The video conferencing technology uses the SIP protocol in IP based networks. The traditional network uses H.323.
Advantages of SIP:
• SIP is more streamlined protocol developed specially for IP telephony.
SIP can take control over the other protocols which cannot done by the H.323
• Call initiation and ending in SIP will be obtained by two communication tools helps to track the location of user.
• SIP can be easily updated like a HTML page.
(advantage of sip for VoIP, 2006
Establishment of Push-to-Talk communication:
SIP framework facilitates the PTT communication by providing end-to-end connection in all devices. SIP introduces a stack that is relevant in handling the wireless SIP User Agents (UAs).
In normal standard SIP UA, the other UA communicate directly with the end devices which takes time and sometimes the connection will break which leads to loss of data and takes long time to get back to the normal state. But in PTT communication PoC server catches the status and settings of the wireless device. When the wireless network changes its status SIP updates the PoC server and when another device wants to connect the particular device, it checks with the PoC server and determines the connection to receive the data. This process makes faster connection between end users in PTT communication and also effectively prevents bandwidth use. (Vlasach, 2007)
Reference:
Matt, Vlasach (2007, June). SIP-Based Push-to-talk Moving into Enterprise Territory. Retrieved November 25, 2007, from Network Computing Web site: http://www.networkcomputing.com/showArticle.jhtml?articleID=199905073
Rosenberg (2002, June). Network working Group. Retrieved November 23, 2007, from SIP Session Initiation protocol Web site: http://www.ietf.org/rfc/rfc3261.txt
(April 2006). White paper: advantage of sip for VoIP. Retrieved September 22, 2007, Web site: http://www.nokiaforbusiness.com/documents/WhitePaper_SIP_for_VoIP.pdf?doc=DL&ind=general