Motorola Corporation

Other

Motorola Solutions, Inc.

Mario F Derango

Daniel J McDonald

Gregory A Dertz

Michael F Korus

John W Maher

Russell A Marten

Surender Kumar

Randy L Ekl

Mark L Shaughnessy

James Earl Mathis

Michael H Retzer

Robert A Biggs

Joseph E Phillips

James E Eastwood

Michael Joseph Crowley

Thomas Patrick McGovern

Bhavesh G Patel

Paul John Smith

In one embodiment of the present invention, an access point () receives a multicast packet intended for a particular multicast group. Upon receipt, the access point only rebroadcast the multicast packet over a wireless segment if it determines that there is at least one wireless subscriber unit () belonging to the particular multicast group and associated with the access point that did not originate the multicast packet. Optionally, if the multicast packet signals an automatic rebroadcast of the multicast packet over the wireless segment, the access point automatically rebroadcasts the multicast packet without determining whether there is at least one wireless subscriber unit belonging to the particular multicast group and associated with the access point that did not originate the multicast packet.

Method for preserving wireless resources in a wireless local area network

Call control methods are disclosed for a multi-zone, packet-based communication system using zone controller/RPEs incorporating a reservation proxy function. Participating zone controller/RPEs () receive and join a multicast group address to be used for a call, and exchange RSVP signaling messages across one or more inter-zone, packet network links () to reserve communication resources for the call on behalf of participating devices in various zones. In the preferred embodiment, the zone controllers use IGMPv3 messages to specify other participating zone controllers as valid senders, thereby receiving desired control information for the duration of the call without being encumbered by undesired payload information.

Reservation proxy function supporting filtering of multicast traffic in packet-based communication systems

Methods are disclosed for limiting the scope of flooding of dense mode IP multicast calls. A multicast scope value (e.g., TTL scope or hop limit) is determined for each call based on the locations of participating devices for the call at one or more destination sites, zones or zone clusters. The multicast scope value is adjusted based on user location, as wireless users may roam from site to site or zone to zone (or zone cluster). When a user sources packets for a call, the packets include the multicast scope value. The packets are transported, according to dense mode routing protocols, across various router interfaces of a packet network. The router interfaces are assigned various thresholds based on their location in the network. Packets are not flooded across router interface(s) having thresholds that exceed the packet's multicast scope value. Thus, through judicious choice of multicast scope value, the flooding of packets for a call may be constrained to within a single zone (or zone cluster), or allowed to proceed to remote zones.

Dense mode IP multicast call scoping in a wireless communication system

The device ( ) includes a processor ( ) coupled to a memory ( ) containing a program adapted to control the processor ( ) to manage communications between data communications systems. The management method includes the steps of receiving a first message sent from a first data communications system ( ) comprising a plurality of blocks ( ), determining whether the blocks ( ) of the first message are transferable or non-transferrable, sending a request repeat message to the first data communications system ( ) to request the first data communications system ( ) to resend the non-transferable blocks ( ) of the first message if the processor ( ) determines that any of the blocks ( ) of the first message are non-transferable, and sending the transferable blocks ( ) in the form of a second message comprising a first plurality of fragments ( ) to a second data communications system ( ) without waiting for the first data communications system ( ) to resend the non-transferable blocks ( ).

Device and method for managing communications between data communications systems

Network access delays are minimized by using affiliation messages to pre-establish communications in a wireless communication network (100). A controller (102), upon receiving an affiliation message from a first site (104), establishes connections between the first site and a second site (105), the connections being uniquely associated with a talkgroup/site affiliation indicated by the affiliation message. Additional sites can be added by modifying the connection to include the additional sites. Using a multicast SVC as the connection between the first and second site eliminates the need for a multicast server and its associated delays.

Method for pre-establishing communications in a wireless communication

A wireless communication system 200 comprises a connectionless packet network 201 coupled to a plurality of sites 203-208 that are in wireless communication with a plurality of subscriber units 210-217 logically arranged into a plurality of talk groups having corresponding talk group identifications. In one embodiment, each site maintains mappings 220-225 of at least one multicast address to at least one talk group identification. In another embodiment, individual subscriber units maintain such mappings 320. When a subscriber unit affiliates with a given site and talk group (501, 601), the site identifies a multicast address corresponding to the talk group. Based on the multicast address, the site can participate in traffic targeted for the multicast address and, consequently, for the talk group. In this manner, mobility Processing is decentralized, system calability is improved and call setup delays are minimized.

Wireless communication system incorporating multicast addressing and

A packet non-replicating comparator device for use in a digital simulcast radio communication system generates a single seed copy of a timestamped information data packet (per channel) for transmission to either a multicast capable packet-switched network or to a packet duplicator coupled to a unicast capable packet-switched network. The multicast capability of packet-switched networks is utilized to simplify the hardware and software complexity at the comparator site, by assigning the responsibility for performing simulcast (timestamped) packet replication and distribution (to the appropriate transmitters) to the coupled packet-switched network. As a result, the elimination of the comparator performed function of sourcing multiple (replicated) packets of a seed copy frees up valuable link bandwidth and improves processing capability and makes possible the generation of multiple non-replicated packets corresponding to associated ones of multiple channels by a single comparator device.

Packet non-replicating comparator device for digital simulcast packet

In a digital multi-channel simulcast system, a redundant centralized timestamping device acts as a simulcast controller for multiple channels simultaneously. All packets within a regional multi-channel system which require simulcast transmission are sent to a central timestamping device which determines the appropriate launch timestamp for each packet and attaches it thereto. The timestamping device is able to support concurrent timestamping sessions for each channel of a multiple channel system and can be dynamically assigned (trunked) to service any given radio channel on a packet by packet, call by call, or less frequent basis.

Digital multi-channel simulcast system with centralized timestamping

A packet voting server and associated method for performing voting services on multiple radio channels simultaneously and including capability to be dynamically assigned (trunked) to service any given radio channel, for example, on a packet by packet, call by call, or less frequent basis.

Packet voting server and associated method for performing voting

Network access delays are minimized by using affiliation messages to pre-establish communications in a wireless communication network (100). In a first embodiment, connections between a site and a multicast server are not pre-assigned. A controller (102), upon receiving an affiliation message from a site (104), establishes connections between the site and a multicast server (111), the connections being uniquely associated with a talkgroup/site affiliation indicated by the affiliation message. In a second embodiment, connections between the site and the multicast server are pre-arranged. Thus, responsive to the affiliation message received from the site, the controller informs the multicast server that a talkgroup is affiliated with the site. Regardless of whether the first or second embodiment is used, the multicast server routes packetized information corresponding to the talkgroup to those sites with which the talkgroup is affiliated.

Growing community of inventors

Wauconda, IL, United States of America

Mario F Derango