Local addressing of mobile units in a WLAN with multicast packet addressing

• US 20020150098A1
• Filed: 04/13/2001
• Published: 10/17/2002
• Est. Priority Date: 09/29/2000
• Status: Active Grant

• Current Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Original Assignee: Symbol Technologies, Inc. (Zebra Technologies Corporation)
• Inventors: Sharony, Jacob
• Granted Patent: US 6,577,609 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

In a wireless local area network, a method and apparatus for providing a multicast address data packet from a single access point to one or more mobile units coupled to the access point is disclosed. A data frame packet is formed containing two or more data packets, each packet targeted for different mobile units having unique unicast addresses. The data frame is transmitted to the mobile units and each of the mobile units derives the proper data intended for it from the data packets, by examining the unicast addresses of each packet.

Claims

1. A method of operating a packet data communications network including a plurality of access points and a plurality of remote mobile wireless units, at least two of the mobile units being capable of communicating with at least one of the access points, and when located within a predetermined range there from, being associated with a single one of such access points, comprising:

establishing an association between the mobile units and the access points utilizing a packet frame addressing protocol including a multicast address;

receiving in one of the access points at least two distinct sequences of packets addressed to at least two mobile units respectively associated with the access point;

forming a frame in the access point, with a multicast address including the address of at least two of the mobile units, and including in the data field of the frame unicast packets addressed to each of at least two of the mobile units; and

transmitting the frame to the mobile units by the one access point.

2. A method as defined in claim 1, wherein the wireless communications link in the data communications network is an IEEE 802.11 network.

3. A method as defined in claim 1, when the mobile unit includes a Windows CE operating system with a Winsock API.

4. A method as defined in claim 1, wherein the mobile unit includes a bar code reader.

5. A method as defined in claim 1, wherein the mobile unit includes a voice communications device.

6. A method as defined in claim 2, wherein the multicast address is defined at the IEEE 802.11 MAC frame level.

7. A method as defined in claim 6, wherein the data field of the IEEE 802.11 MAC frame includes at least two IP packets with different unicast IP addresses.

8. An article comprising a computer-readable medium that stores computer-executable instructions for operating a packet data communications network including a plurality of access points and a plurality of remote mobile wireless units, at least some of the mobile units being capable of communicating with at least one of the access points, and when located within a predetermined range there from being associated with a single one of such access points, the instructions causing a computer to:

establish an association between the mobile units and the access points utilizing a packet frame addressing protocol including a multicast address;

receive in one of the access points at least two distinct sequences of packets addressed to at least two mobile units respectively associated with the access point;

form a frame in the access point, with a multicast address including the address of at least two of the mobile units, and including in the data field of the frame unicast packets addressed to each of at least two of the mobile units; and

9. An article comprising a computer-readable medium that stores computer-executable instructions for operating a packet data communications network including a plurality of access points and a plurality of remote mobile wireless units, at least some of the mobile units being capable of communicating with at least one of the access points, and when located within a predetermined range therefrom being associated with a single one of such access points, the instructions causing a computer to:

establish an association between the mobile units and the access points utilizing a packet frame addressing protocol including a multicast address;

receive in one of the access points at least two distinct sequences of packets addressed to at least two mobile units respectively associated with the access point;

form a frame in the access point, with a multicast address including the address of at least two of the mobile units, and including in the data field of the frame unicast packets addressed to each of at least two of the mobile units; and

transmit the frame to the mobile units by the one access point.