Apparatus and method adapted for directional bandwidth reservation with fixed announcement slot in wireless networks

• US 20090232103A1
• Filed: 08/21/2008
• Published: 09/17/2009
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Bachrach, Yuval, Trainin, Solomon, Kesselman, Alex
• Granted Patent: US 8,897,268 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H04B 7/0682 using phase diversity (e.g. phase sweeping)
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

An embodiment of the present invention provides an apparatus, comprising a transceiver operable in a wireless personal area network, wherein the transceiver is configured to communicate with a coordinator and at least one receiver and wherein the transceiver and the coordinator use a directional reservation of free channel time blocks using contention-based slots, by selecting uniformly at random contention slots by the transceiver and transmitting a bandwidth reservation request message specifying the requested reservation period using directional transmission pointed towards the coordinator.

Claims

1. An apparatus, comprising:

a transceiver operable in a wireless personal area network, wherein said transceiver is configured to communicate with a coordinator and at least one receiver; and

wherein said transceiver and said coordinator use a directional reservation of free channel time blocks using contention-based slots, by selecting uniformly at random contention slots by said transceiver and transmitting a bandwidth reservation request message specifying the requested reservation period using directional transmission pointed towards said coordinator.

2. The apparatus of claim 1, wherein at the beginning of said free time channel time block there is a pre-defined number of contention slots used by devices to transmit bandwidth reservation requests to the coordinator followed by an announcement slot used by said coordinator to announce the granted bandwidth reservation if any.

3. The apparatus of claim 2, wherein said contention slot duration must be long enough to accommodate transmissions.

4. The apparatus of claim 1, wherein said coordinator responds to said transceiver and/or other devices using directional or quasi-omni-directional transmission with a bandwidth grant message that specifies links and an allocated reservation period.

5. The apparatus of claim 4, wherein if multiple senders have succeeded with request transmission, said coordinator selects one of them.

6. The apparatus if claim 1, wherein the number of contention slots can be either fixed or announced by the coordinator in the beacon frame and said coordinator may also allow certain non-interfering links to utilize an allocated channel time block as specified in said bandwidth grant message.

7. The apparatus of claim 1, wherein said coordinator uses a directional antenna for reception during contention slots by shortening contention slots to accommodate only the transmission of a preamble allowing the coordinator to perform antenna training and lock onto the directional signal and wherein said preamble is followed by directional transmission of a bandwidth reservation request message.

8. The apparatus of claim 1, wherein a bandwidth reservation request message may ask for a time period longer than the available time in an unallocated channel time block under consideration and said coordinator may reserve to said transceiver the difference between the requested time and the actually allocated time in the future without a need to send an extra bandwidth reservation request.

9. The apparatus of claim 8, wherein if the number of devices in said WPAN that generate bursty traffic does not exceed the number of contention slots, then said Coordinator may associate every such device with a dedicated contention slot by making an advertisement in the beacon frame, thereby removing contention.

21. The machine-accessible medium of claim 9, further comprising said instructions causing said machine to perform operations further comprising requiring said contention slot duration to be long enough to accommodate transmissions.

22. The apparatus of claim 1, wherein contention periods can be located at the beginning as well as in the middle of free channel time blocks if said Coordinator advertises them in a beacon.

10. A method, comprising:

using a transceiver operable in a wireless personal area network to communicate with a coordinator and at least one receiver; and

wherein said transceiver and said coordinator use a directional reservation of free channel time blocks using contention-based slots, by selecting uniformly at random contention slots by said transceiver and transmitting a bandwidth reservation request message specifying the requested reservation period using directional transmission pointed towards said coordinator.

11. The method of claim 10, further comprising pre-defining a number of contention slots at the beginning of said free time channel time block used by devices to transmit bandwidth reservation requests to the coordinator followed by an announcement slot used by said coordinator to announce the granted bandwidth reservation if any.

12. The method of claim 11, further comprising requiring said contention slot duration to be long enough to accommodate transmissions.

13. The method of claim 10, further comprising responding by said coordinator to said transceiver and/or other devices using directional or quasi-omni-directional transmission with a bandwidth grant message that specifies links and an allocated reservation period, which can be less than or equal to a requested period.

14. The method of claim 13, wherein if multiple senders have succeeded with request transmission, said coordinator selects one of them.

15. The method of claim 10, wherein the number of contention slots can be either fixed or announced by the coordinator in the beacon frame and said coordinator may also allow certain non-interfering links to utilize an allocated channel time block as specified in said bandwidth grant message.

16. The method of claim 15, further comprising using by said coordinator a directional antenna for reception during contention slots by shortening contention slots to accommodate only the transmission of a preamble, allowing the coordinator to perform antenna training and lock onto the directional signal and wherein said preamble is followed by directional transmission of a bandwidth reservation request message.

17. The method of claim 10, asking for a time period longer than the available time in an unallocated channel time block under consideration by a bandwidth reservation request message and reserving by said coordinator to said transceiver the difference between the requested time and the actually allocated time in the future without a need to send an extra bandwidth reservation request.

18. The method of claim 17, further comprising associating by said coordinator every device with a dedicated contention slot by making an advertisement in the beacon frame, thereby removing contention if the number of devices in said WPAN that generate bursty traffic does not exceed the number of contention slots,

19. A machine-accessible medium that provides instructions, which when accessed, cause a machine to perform operations comprising:

configuring a transceiver operable in a wireless personal area network to communicate with a coordinator and at least one receiver; and

configuring said transceiver and said coordinator to use a directional reservation of free channel time blocks using contention-based slots, by selecting uniformly at random contention slots by said transceiver and transmitting a bandwidth reservation request message specifying the requested reservation period using directional transmission pointed towards said coordinator.

20. The machine-accessible medium of claim 19, further comprising said instructions causing said machine to perform operations further comprising pre-defining a number of contention slots at the beginning of said free time channel time block used by devices to transmit bandwidth reservation requests to the coordinator followed by an announcement slot used by said coordinator to announce the granted bandwidth reservation if any.

23. An apparatus, comprising:

a transceiver operable as coordinator in a wireless personal area network, wherein said transceiver is configured to communicate with at least one receiver; and

wherein said coordinator advertises said reservation during an announcement slot.

24. The apparatus of claim 23, wherein at the beginning of said free time channel time block there is a pre-defined number of contention slots used by devices to transmit bandwidth reservation requests to the coordinator followed by an announcement slot used by said coordinator to announce the granted bandwidth reservation if any.

25. The apparatus of claim 24, wherein said contention slot duration must be long enough to accommodate transmissions.

26. The apparatus of claim 23, wherein said coordinator uses a directional antenna for reception during contention slots by shortening contention slots to accommodate only the transmission of a preamble allowing the coordinator to perform antenna training and lock onto the directional signal and wherein said preamble is followed by directional transmission of a bandwidth reservation request message.