Apparatus for selecting an optimum access point in a wireless network

• US 7,248,574 B2
• Filed: 02/18/2004
• Issued: 07/24/2007
• 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, Bridge, Laura
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): HOANG, THAI D
• Application Number:
  US10/780,804
• Publication Number:
  US 20040166866A1
• Time in Patent Office: 1,252 Days
• Field of Search: 455436-444, 455450-4522, 455/454, 4554321-4322, 370329-338, 370342-348
• US Class Current: 370/338
• 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. Apparatus for use by a wireless device in a wireless communications environment including multiple access points and stations, wherein stations gain network access by associating with one of the access points, comprising:

data processing apparatus for associating the wireless device with a current access point on a first channel;

data processing apparatus for automatically collecting, by the wireless device, information about access points operating on other channels, including indications of transmit power backoff;

data processing apparatus for ascertaining, by the wireless device, whether the wireless device should attempt to associate with an alternative access point operating on a second channel, the ascertaining logic employing, at least in-part, indications of signal strengths of transmissions from the alternative access point, and technology type employed by the alternative access point;

data processing apparatus for requesting association with the alternative access point if it is ascertained that the wireless device should attempt to associate with said alternative access point, wherein the data processing apparatus for ascertaining obtains an indication of expected data rate of service by the alternative access point, and ascertains that the wireless device should attempt to associate with the alternative access point operating on said second channel if the alternative access point on said second channel has a greater expected data rate than an actual data rate provided by the current access point; and

data processing apparatus operable if requested association is approved by the alternative access point to cause the wireless device to become associated with that alternative access point.

2. The apparatus of claim 1 wherein the data processing apparatus for ascertaining ascertains by:

calculating a first biased distance between the wireless device and the current access point based on “

x”

samples;

calculating a second biased distance between the wireless device and the alternative access point operating on said second channel based on “

y”

samples where “

y”

is less than “

x”

; and

ascertaining that the alternative access point operating on said second channel is closer than the current access point if the second biased distance is less than the first biased distance.

3. The apparatus of claim 1 wherein the data processing apparatus for requesting association requests association by sending a bid message to the alternative access point operating on said second channel prior to disassociating from the current access point.

4. The apparatus of claim 1 wherein the alternative access point is operating at a purposefully attenuated transmission signal strength, and wherein the ascertaining data processing apparatus also employs maximum potential signal strength of the alternative access point for ascertaining whether the wireless device should attempt to associate with the alternative access point.

5. The apparatus of claim 1 wherein the ascertaining data processing apparatus also employs technology type being employed by devices associated with the alternative access point.