Wireless adapter with auxiliary radio channel for advanced channel scanning

• US 8,630,255 B1
• Filed: 09/17/2007
• Issued: 01/14/2014
• Est. Priority Date: 09/19/2006
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Kunz, Manfred, Schmalz, Joachim
• Primary Examiner(s): Yao, Kwang B
• Assistant Examiner(s): Elpenord, Candal
• Application Number:
  US11/901,435
• Time in Patent Office: 2,311 Days
• Field of Search: 370/338
• US Class Current: 370/331
• CPC Class Codes: H04B 7/0825 with main and with auxiliary or diversity antennas
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/0088 Scheduling hand-off measurements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 74/06 using polling

Abstract

A wireless device for wireless communication in a wireless area network. The wireless device includes a main radio channel for exchanging data with an access point in the wireless area network, as well as an auxiliary radio channel for scanning for availability of other access points in the wireless area network.

Claims

1. A wireless device, comprising:

a first radio channel including transmit capabilities and receive capabilities respectively configured for transmission and reception of data, with a first access point in a wireless local area network, over a first channel associated with the first access point, wherein the transmission and reception of data over the first channel is implemented pursuant to a protocol for data transmission and reception as defined by a wireless standard, and wherein the wireless standard further defines a scanning protocol for searching for access points within the wireless local area network;

a second radio channel including only receive capabilities configured to scan, pursuant to the scanning protocol defined by the wireless standard, for a second access point over a second channel associated with the second access point, wherein the second radio channel (i) is separate from the first radio channel and (ii) does not include a transmitter due to the second radio channel including only receive capabilities, wherein the second radio channel is further configured to scan for the second access point pursuant to a configurable channel list, wherein the configurable channel list indicates (i) a first group of channels that are enabled to be scanned by the second radio channel, (ii) a second group of channels that are not enabled to be scanned by the second radio channel, and (iii) for each channel in the first group of channels, an indication of a corresponding time period for scanning the corresponding channel in the first group of channels, and wherein the second channel is included in the first group of channels; and

a controller configured to facilitate a handoff procedure to switch the transmission and reception of data over the first channel associated with the first access point to the second channel associated with the second access point.

2. The wireless device according to claim 1, wherein the second radio channel is further configured to, prior to an initiation of the handoff procedure, scan for the second access point.

3. The wireless device according to claim 1, wherein:

the second radio channel is configured to scan for the second access point by passively listening for a transmission from the second access point on the second channel; and

the second radio channel is configured to passively listen for the transmission from the second access point on the second channel while the first radio channel simultaneously transmits and receives data over the first channel.

4. The wireless device according to claim 1, wherein for said each channel in the first group of channels, the indication of the corresponding time period for scanning the corresponding channel in the first group of channels is configurable.

5. The wireless device according to claim 1, wherein the configurable channel list includes a configurable time period to wait between scanning of the channels in the first group of channels.

6. The wireless device according to claim 1, wherein the wireless device maintains a channel database that includes the configurable channel list and an indication of presence of usable frames in individual channels included in the configurable channel list and wherein the channel database is updated pursuant to scanning activities of the second radio channel.

7. The wireless device according to claim 6, wherein:

the wireless device further comprises an interface to a host device; and

the channel database is communicated to the host device over the interface.

8. The wireless device according to claim 1, wherein the second radio channel pre-authorizes the wireless device for data communication with other access points in the wireless network.

9. The wireless device according to claim 1, wherein:

the first radio channel is associated with a main antenna;

the second radio channel is associated with an auxiliary antenna; and

the auxiliary antenna is physically smaller than the main antenna.

10. The wireless device according to claim 1, wherein the second radio channel is configured to, while scanning pursuant to the scanning protocol defined by the wireless standard, scan for access points within the wireless local area network, wherein each access point is scanned for an amount of time that is configurable by the controller.