Dynamic wireless local area network with interactive communications within the network

• US 5,875,186 A
• Filed: 01/23/1997
• Issued: 02/23/1999
• Est. Priority Date: 06/25/1993
• Status: Expired due to Term

• Current Assignee: Avaya Incorporated
• Original Assignee: Netwave Technologies Limited
• Inventors: Rosen, David B., Belanger, Philip H., Baugh, William N.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Jung, Min
• Application Number:
  US08/787,843
• Time in Patent Office: 761 Days
• Field of Search: 370/331, 370/332, 370/338, 370/252, 455/33.1, 455/33.2, 455/33.4, 379/60, 379/63
• US Class Current: 370/331
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/7143 Arrangements for generation of hop patterns
• CPC Class Codes: H04B 1/7156 Arrangements for sequence synchronisation
• CPC Class Codes: H04B 2001/71563 Acquisition
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/006 in the downlink, i.e. towards the terminal
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A network with wireless links is a dynamic learning system which allows a mobile (wireless) unit to determine which access point (wired) unit provides the mobile unit with the best communications as the mobile unit roams within an area and from area to area. As a mobile unit enters a new area, it scans the area to find an access point unit. After the mobile unit is verified by the access point unit, the mobile unit receives updated information about other access points in the area, including information indicating which access point units are within wireless transmission range of the mobile unit as well as multiple values indicating a communication range for a particular access point unit to the mobile unit. The information is updated as the system gathers new information through the mobile units and access point units within the system area. The more mobile units that enter and leave the area, the more information is gathered by the access point units functioning in the system and the more information the system learns. A mobile unit can also decide to switch to a new access point unit when the quality of service degrades by accessing information about access point units within the system.

Claims

1. A method of operating a local area network including at least one mobile unit and a plurality of access point units, the access point units being connected to each other, the method comprising the steps of:

the mobile unit receiving at least one wireless transmission from at least one of the access point units, the at least one (wireless) transmission including information indicative of which of the access point units are within radio range of the mobile unit, the at least one wireless transmission not being solicited by the mobile unit;

storing the information indicative of which access point units are within (wireless radio transmission) range of the mobile unit;

updating the stored information when the access point units or any other mobile units receive new information indicative of which of the access point units are within wireless transmission range of the mobile unit;

the mobile unit determining that it is no longer to be associated with a first of the access point units and that it is to be associated with a second of the access point units; and

the mobile unit establishing communication with the second access point unit using the stored information indicative of which access point units are within wireless transmission range of the mobile unit.

2. The method of claim 1, wherein each access point unit communicates using a particular radio frequency hopping sequence, and wherein the at least one wireless transmission received by the mobile unit includes information indicative of the radio frequency hopping sequence of each respective access point unit.

3. The method of claim 1, wherein the information indicative of which of the access point units are within wireless transmission range of the mobile unit includes, for each access point unit, one of a plurality of values indicative of wireless transmission range.

4. The method of claim 3, wherein there are at least three values indicative of the wireless transmission range:

one value indicating that the associated access point unit is likely to be "near" the mobile unit, one value indicating that the associated access point unit is likely to be "far" from the mobile unit, and one value indicating that the range between the associated access point unit and the mobile unit is "unknown".

5. The method of claim 1, wherein the at least one wireless transmission received by the mobile unit includes information indicative of a radio frequency hopping sequence used by an access point unit.

6. The method of claim 1, wherein the information indicative of which of the access point units are within wireless transmission range of the mobile unit is received by the mobile unit in multiple transmissions, wherein information indicative of the range to each respective access point unit is received from a transmission from that particular access point unit and not from transmissions from other access point units.

7. The method of claim 1, wherein the information indicative of which of the access point units are within wireless transmission range of the mobile unit is received from one access point unit.

8. The method of claim 1, wherein updating the information comprises the steps of:

the mobile unit scanning wireless transmissions broadcast by other access point units and not by the access point unit associated with the mobile unit;

the mobile unit sending wireless transmissions with the new information to the access point unit associated with the mobile unit; and

the access point unit broadcasting the updated information to all mobile units associated with the access point unit.

9. The method of claim 1, further comprising the step of the mobile units sending and receiving the updated information to and from the access point units when the mobile units or access point units receive the new information.

10. The method of claim 1, wherein the information is updated when the mobile units broadcast a transmission with the new information or when the access point units send a transmission with the new information.

11. A local area network comprising:

a plurality of access point units connected to each other;

at least one mobile unit receiving at least one wireless transmission from at least one of the access point units, the at least one transmission including information indicative of which of the access point units are within wireless transmission range of the mobile unit, the at least one transmission not being solicited by the mobile unit;

means for storing the information indicative of which access point units are within wireless transmission range of the mobile unit;

means for updating the stored information when the access point units or any other mobile units receive new information indicative of which of the access point units are within wireless transmission range of the mobile unit;

means for determining the mobile unit is no longer to be associated with a first of the access point units and that it is to be associated with a second of the access point units; and

means for establishing communication with the second access point unit using the stored information indicative of which access point units are within wireless transmission range of the mobile unit.