Abstract: A method is disclosed that includes sending (304) a first full header from a source compressor (106) to a destination decompressor (112) wherein the source compressor and the destination decompressor are a part of a symmetrical configuration. An IP packet including the full header is compressed into a first compressed header (310) based on the context established in the first full header. The first compressed header is sent (312) from the source compressor to the destination decompressor. The compressor receives (322) a second full header from the destination compressor wherein the second full header indicates that the destination decompressor did not receive the first full header. The second full header can include a modified field or has an incremented generation identification. The source compressor sends (336) another full header to the destination decompressor.

Abstract: A system and method for managing call affiliation in a communication system having a plurality of communication units. When a public call announcement is initiated, a broadcast data message is transmitted to the communication units identifying a public announcement talkgroup for the call. Upon receiving the broadcast data message, each of the communication units waits a random amount of time before attempting to affiliate to the public announcement talkgroup. At the same time, each communication unit also monitors other messages on the control channel. Each communication unit joins the public announcement talkgroup upon the first of either (1) receiving an affiliation grant in response to an affiliation request transmitted by the communication unit, or (2) detecting an affiliation grant being transmitted to a different communication unit attempting to affiliate to the same talkgroup.

Abstract: A system and method for managing call affiliation in a communication system having a plurality of communication units. When a public call announcement is initiated, a broadcast data message is transmitted to the communication units identifying a public announcement talkgroup for the call. Upon receiving the broadcast data message, each of the communication units waits a random amount of time before attempting to affiliate to the public announcement talkgroup. At the same time, each communication unit also monitors other messages on the control channel. Each communication unit joins the public announcement talkgroup upon the first of either (1) receiving an affiliation grant in response to an affiliation request transmitted by the communication unit, or (2) detecting an affiliation grant being transmitted to a different communication unit attempting to affiliate to the same talkgroup.

Abstract: A method is disclosed that includes sending (304) a first full header from a source compressor (106) to a destination decompressor (112) wherein the source compressor and the destination decompressor are a part of a symmetrical configuration. An IP packet including the full header is compressed into a first compressed header (310) based on the context established in the first full header. The first compressed header is sent (312) from the source compressor to the destination decompressor. The compressor receives (322) a second full header from the destination compressor wherein the second full header indicates that the destination decompressor did not receive the first full header. The second full header can include a modified field or has an incremented generation identification. The source compressor sends (336) another full header to the destination decompressor.

Abstract: A method and apparatus for maintaining communications between a mobile computer and a mobile subscriber unit is disclosed. The method and apparatus comprise determining whether a connection is available between the mobile subscriber unit and a radio communications system. If a connection is available, then the method and apparatus include retrieving a first IP address for the mobile computer from the radio communications system. Then, the method and apparatus comprise caching the first IP address in the mobile subscriber unit for use by the mobile computer. Finally, the method and apparatus include utilizing the first IP address even if the radio communications system is unavailable and updating the first IP address with a second IP address obtained from the radio communications system when the radio communications system is available.