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METHOD 0F 3RD PARTY CONTROL FOR IP MULTICAST GROUP MEMBERSHIP IN 2-WAY RADIO SYSTEMS

IP.com Disclosure Number: IPCOM000009346D
Original Publication Date: 1999-Jun-01
Included in the Prior Art Database: 2002-Aug-19
Document File: 2 page(s) / 191K

Publishing Venue

Motorola

Related People

Mike Korus: AUTHOR [+4]

Abstract

IP Multicast is a packet based technology for transmitting information from a single source to multiple destinations. IP multicast is being pursued as the voice transport protocol for next generation RNSG (two-way radio) infrastructures. IP Multicast is a receiver oriented protocol. To receive IP Multicast packets, as described in RFC1112, hosts (i.e. base/repeaters) configure their LAN hardware and software stack to receive IP Multicast packets. In addition, hosts generate and transmit IGMP (Internet Group Management Protocol) join mes- sages on their LAN to inform neighboring routers which IP Multicast groups they wish to join. The routers then construct IP multicast distribution trees by sharing group membership information using an IP Multicast routing protocol.

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Developments Technical 0 M MO7VROLA

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METHOD 0~ 3RD PARTY CONTROL FOR IP I\J~ULTICAST

GROUP MEMBERSHIP IN 2-WAY RADIO SYSTEMS

by Mike Korus, George Popovich, Mario DeRango and RIJSS Marten

INTRODUCTION

  IP Multicast is a packet based technology for transmitting information from a single source to multiple destinations. IP multicast is being pursued as the voice transport protocol for next generation RNSG (two-way radio) infrastructures. IP Multicast is a receiver oriented protocol. To receive IP Multicast packets, as described in RFC1112, hosts
(i.e. base/repeaters) configure their LAN hardware and software stack to receive IP Multicast packets. In addition, hosts generate and transmit IGMP (Internet Group Management Protocol) join mes- sages on their LAN to inform neighboring routers which IP Multicast groups they wish to join. The routers then construct IP multicast distribution trees by sharing group membership information using an IP Multicast routing protocol.

PROBLEM WITH EXISTING PROTOCOLS

  Methods of joining and leaving IP Multicast groups are well documented in IETF standards. RFC1112 defines host requirements for joining IP Multicast groups. IETF drafts igmp-v2 and igmp-v3 add numerous enhancements to RFC1112 including a method to leave IP Multicast groups. However, none of these standards or drafts discuss

methods of controlling which IP Multicast group a host may join or leave, which is critical in our appli- cation as described in the following paragraph.

  One of the problems encountered with IP Multicast transport in a wireless/radio system is the assignment of a base/repeater to an IP Multicast

group. This problem is unique to wireless systems
(i.e. two-way radio, cellular, paging etc.) since mul- tiple base/repeaters mai exist at a site and any base/repeater can be ass@ed to the call. In order for a base/repeater to paiticipate in a call (i.e. dis- patch voice, private call, telephone interconnect, etc.) the base/repeater must join the "assigned" IP Multicast group. By itself, the base/repeater can not determine wh...