Method of establishing communication channel between handsets and network-based servers
Original Publication Date: 2003-Jun-16
Included in the Prior Art Database: 2003-Jun-16
This invention enables a network server to determine the need for a secondary in-band communication channel in addition to a signaling channel with clients and the means to establish them. The secondary channel applies different Quality Of Service (QoS) to the data types within this channel (user data and in-band signaling). The server determines the extent of signaling for the call and this is effected over a secondary signaling channel within the traffic channel (TCH) with an enhanced QoS for the in-band signaling. In one embodiment, the channel is essentially application level messages over the Internet Protocol (IP), making it an efficient method of communication. In another embodiment, the SIP INFO messages are used to encapsulate and carry these messages. This mechanism was introduced in support of Dispatch Services in CDMA 1X networks. The Dispatch Applications Server accepts and processes Dispatch and other service requests from handhelds and Mobile Stations (MS). The server and the MS communicate on the specified communication channel, independent of normal signaling for call processing. The invention proposes one method of establishing this communication channel using SIP signaling, while meeting the stringent requirement of a 1500 ms call setup delay.