Wireless channel selection method and system using scanning for identifying access point

• US 7,116,979 B2
• Filed: 02/18/2004
• Issued: 10/03/2006
• Est. Priority Date: 02/24/2003
• Status: Active Grant

• Current Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Original Assignee: Autocell Laboratories Incorporated
• Inventors: Backes, Floyd, Vacon, Gary, Callahan, Paul, Hawe, William
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): Ewart, James D
• Application Number:
  US10/781,259
• Publication Number:
  US 20040165557A1
• Time in Patent Office: 958 Days
• Field of Search: 455/434, 455/447, 455/450, 455/451, 455/452.1, 455/454, 455/455, 455/463, 455/464, 455/509, 455/515, 370/329, 370/330, 370/332, 370/338, 370/341, 370/343, 370/431, 370/437, 370/464, 370/480
• US Class Current: 455/434
• CPC Class Codes: H04B 17/27 for locating or positioning the transmitter
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 47/125 by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/10015 Access to distributed or replicated servers, e.g. using brokers
• CPC Class Codes: H04W 16/04 Traffic adaptive resource partitioning
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 28/08 Load balancing or load distribution transferring a connection for handling the traffic H04W36/22; wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/0862 of same hierarchy level
• CPC Class Codes: H04W 28/0983 for optimizing bandwidth or throughput
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 : for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/20 : for optimising the interference level
• CPC Class Codes: H04W 36/32 : by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 4/02 : Services making use of location information
• CPC Class Codes: H04W 40/08 : based on transmission power
• CPC Class Codes: H04W 40/18 : based on predicted events
• CPC Class Codes: H04W 40/36 : due to handover
• CPC Class Codes: H04W 48/06 : based on traffic conditions
• 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 48/17 : Selecting a data network PoA [Point of Attachment]
• CPC Class Codes: H04W 48/20 : Selecting an access point
• CPC Class Codes: H04W 52/0216 : using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/10 : Open loop power control
• CPC Class Codes: H04W 52/18 : TPC being performed according to specific parameters
• CPC Class Codes: H04W 52/225 : Calculation of statistics, e.g. average, variance
• CPC Class Codes: H04W 52/226 : using past references to control power, e.g. look-up-table
• CPC Class Codes: H04W 52/228 : using past power values or information
• CPC Class Codes: H04W 52/24 : using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/245 : taking into account received signal strength
• CPC Class Codes: H04W 52/246 : where the output power of a terminal is based on a path parameter calculated in said terminal
• CPC Class Codes: H04W 52/247 : where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/283 : Power depending on the position of the mobile
• CPC Class Codes: H04W 52/285 : taking into account the mobility of the user
• CPC Class Codes: H04W 52/286 : during data packet transmission, e.g. high speed packet access [HSPA]
• CPC Class Codes: H04W 52/287 : when the channel is in stand-by
• CPC Class Codes: H04W 52/288 : taking into account the usage mode, e.g. hands-free, data transmission, telephone
• CPC Class Codes: H04W 52/34 : TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/343 : taking into account loading or congestion level
• CPC Class Codes: H04W 52/367 : Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/50 : at the moment of starting communication in a multiple access environment
• 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 64/00 : Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/006 : with additional information processing, e.g. for direction or speed determination
• CPC Class Codes: H04W 72/02 : Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/52 : based on load
• CPC Class Codes: H04W 72/54 : based on quality criteria
• CPC Class Codes: H04W 74/00 : Wireless channel access
• CPC Class Codes: H04W 74/002 : Transmission of channel access control information
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 80/00 : Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 80/04 : Network layer protocols, e.g. mobile IP [Internet Protocol]
• CPC Class Codes: H04W 84/12 : WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 : Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 84/22 : with access to wired networks
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: H04W 92/18 : between terminal devices
• CPC Class Codes: H04W 92/20 : between access points
• CPC Class Codes: Y02B 70/30 : Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

The performance and ease of management of wireless communications environments is improved by a mechanism that enables access points (APs) to perform automatic channel selection. A wireless network can therefore include multiple APs, each of which will automatically choose a channel such that channel usage is optimized. Furthermore, APs can perform automatic power adjustment so that multiple APs can operate on the same channel while minimizing interference with each other. Wireless stations are load balanced across APs so that user bandwidth is optimized. A movement detection scheme provides seamless roaming of stations between APs.

Claims

1. A method for use by an access point in a wireless networking communications environment for selecting a channel, the method comprising the steps of:

scanning a plurality of radio frequency channels during a scan interval;

monitoring each of the scanned channels for indication of utilization of ones of the channels from other access points during the scan interval;

maintaining a channel map having an entry for each of the plurality of radio frequency channels, and if one or more messages was received on a channel, the corresponding entry further including an AP-ID for at least one of the access points that sent a message on the channel;

selecting a channel from the channel map based at least in-part on whether an indication of utilization of the selected channel was detected;

prior to utilizing the selected channel for normal communications, transmitting, on the selected channel during a claim interval, at least one message indicative of an intent to utilize the selected channel;

monitoring, from other access points on the selected channel during the claim interval, for a message from another device indicative of an intent to utilize the selected channel; and

ascertaining whether the access point should commence communications with other wireless devices on the selected channel based upon characteristics of any messages received on the channel.

2. The method of claim 1 wherein the step of maintaining a channel map further includes the step of storing a power level for each AP-ID for each entry in the channel map, and wherein the step of selecting a channel from the channel map selects a channel having either no AP-ID or an AP-ID that has the lowest stored power level.

3. The apparatus of claim 1 wherein the step of ascertaining whether the access point should commence communications with other wireless devices on the selected channel based upon characteristics of the messages received on the selected channel comprises the step of:

evaluating the power level of messages received on the selected channel, and if the power level of messages received on the selected channel is below a threshold, the step of ascertaining indicates that the access point should commence communications with other wireless devices on the selected channel.