Method of managing transmission within a wireless communications network

• US 20090028119A1
• Filed: 07/25/2007
• Published: 01/29/2009
• Est. Priority Date: 07/25/2007
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Avidor, Dan, Ling, Jonathan
• Granted Patent: US 8,094,573 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 72/566 of the information or information source or recipient

Abstract

The method includes sending a request for permission to transmit by each ready node in the wireless network. Each ready node is a node of the wireless network ready to transmit, each request identifies a node in the network that is the destination, and each request is sent over a control channel. An iterative process based on priorities determined for the ready nodes is then performed to determine which ready nodes to block from transmission and which ready nodes to clear for transmission. Transmissions are sent over a payload channel from ready nodes in the clear to transmit state.

Claims

1. A method of managing transmission in a wireless network, comprising:

sending a request for permission to transmit by each ready node in the wireless network, each ready node being a node of the wireless network ready to transmit, each request identifying a node in the network that is the destination, and each request being sent over a control channel;

performing a block operation at each destination node such that each destination node selectively sends Block messages to neighboring nodes based on respective transmission priorities for the ready nodes neighboring the destination node, the block message instructing the neighboring node not to transmit;

performing an announce operation at each ready node to announce a transmission state of the ready node, the transmission state being one of a blocked from transmitting state and a cleared to transmit state, the blocked from transmitting state being a state in which at least one uncleared block message has been received by the ready node, and the cleared to transmit state being a state in which no uncleared block messages have been received at the ready node;

performing a block/clear operation at each destination node such that each destination node selectively sends block messages and clear messages to neighboring nodes based on the transmission state of each neighboring node, the clear message clearing any block message previously sent by the destination node;

repeating the announce and block/clear operations for a number of iterations;

sending transmissions over a payload channel from ready nodes in the clear to transmit state.

2. The method of claim 1, wherein

the control channel is divided into timeslots, each timeslot is divided into minislots, and each minislot is divided into microslots;

and

the request for permission to transmit sent by each ready node is sent at an assigned microslot.

3. The method of claim 2, further comprising:

advertising, by each node, assignment of microslots to the node and to one-slot neighbors of the node over a contention channel;

detecting conflicts with microslot assignments;

choosing randomly a replacement microslot from unused microslots if a conflict is detected.

4. The method of claim 1, wherein the block operation at each destination node comprises:

determining a priority number for each ready node neighboring the destination node;

determining a priority number for the destination node if the destination node is also a ready node;

determining nodes to be blocked based on the determined priority numbers; and

sending a block message to each of the nodes determined to be blocked.

5. The method of claim 4, wherein the determining nodes to be blocked step comprises, for each destination node:

determining the ready node with the highest priority number among a set containing the ready nodes neighboring the destination node and the destination node, if the destination node is a ready node;

determining to block the ready nodes requesting permission to transmit to the destination node if the destination node is determined to have the highest priority number among the set;

determining to block the ready nodes neighboring the destination node that have requested permission to transmit to the destination node if the ready node determined to have the highest priority number among the set has requested permission to transmit to a node other than the destination node; and

determining to block the ready nodes neighboring the destination node, except for the ready node determined to have the highest priority number among the set, if this node requested permission to transmit to the destination node.

6. The method of claim 1, wherein the announce operation at each ready node comprises:

sending an announce message indicating the ready node is in the blocked from transmission state if the ready node has received at least one uncleared block message; and

sending an announce message indicating the ready node is in the cleared to transmit state if the ready node has not received at least one uncleared block message.

7. The method of claim 1, wherein the block/clear operation is performed at each destination node such that each destination node selectively sends block messages or clear messages to neighboring nodes based on the transmission state of each neighboring node and the transmission priority of each neighboring node.

8. The method of claim 1, wherein the block/clear operation performed comprises, for each destination node:

determining a priority number for each ready node neighboring the destination node;

determining a priority number for the destination node if the destination node is also a ready node;

determining the ready node with the highest priority number among a set containing the ready nodes neighboring the destination node and the destination node, if the destination node is a ready node;

determining to block the ready nodes requesting permission to transmit to the destination node if the destination node is determined to have the highest priority number among the set;

determining to block the ready nodes neighboring the destination node that have requested permission to transmit to the destination node if the ready node determined to have the highest priority number among the set has requested permission to transmit to a node other than the destination node;

determining to block the ready nodes neighboring the destination node, except for the ready node determined to have the highest priority number among the set, if this node requested permission to transmit to the destination node;

determining to clear the ready nodes neighboring the destination node that have requested permission to transmit to a node other than the destination node if no nodes neighboring the destination node are in the cleared to transmit state and the ready node with the highest priority number requested permission to transmit to a node other than the destination node; and

determining to clear an identified node neighboring the destination node if no nodes neighboring the destination node are in the cleared to transmit state and the identified neighboring node requests permission to transmit to the destination node, the identified neighboring node being the node neighboring the destination node with the highest priority number.

9. The method of claim 1, further comprising:

sending, from each destination node receiving a transmission on the payload channel, an acknowledgement over the payload channel.

10. The method of claim 4, wherein the determining a priority number for each ready node step determines each priority number based on a serial number of the ready node.

11. The method of claim 10, wherein the determining a priority number for each ready node step determines each priority number based on a serial number of the ready node and the serial number of the destination node.

12. The method of claim 4, wherein the determining a priority number for the destination node step determines the priority number based on a serial number of the destination node.

13. The method of claim 4, wherein the determining a priority number for each ready node step uses a feedback shift register at each ready node to generate a different priority number for each ready node.

14. The method of claim 13, wherein the feedback shift register is clocked at the timeslot rate.

15. The method of claim 4, wherein the determining a priority number for the destination node step uses a feedback shift register at the destination to generate the priority number.

16. The method of claim 14, wherein the feedback shift register is clocked at the timeslot rate.

17. The method of claim 1, wherein the control channel and payload channel are orthogonal channels.

18. A method of managing transmission in a wireless network, comprising:

sending a request for permission to transmit by each ready node in the wireless network, each ready node being a node of the wireless network ready to transmit, each request identifying a node in the network that is the destination, and each request being sent over a control channel;

determining, at each destination node, transmission priorities for neighboring nodes that are ready nodes; and

selectively sending, by each destination node, block messages and clear messages to the neighboring nodes that are ready nodes based on the determined transmission priorities and announced states of the neighboring nodes that are ready nodes, the block message instructing the neighboring node not to transmit, the clear message clearing any block message previously sent by the destination node, and each announced state indicating whether the ready node is blocked or cleared to transmit;

sending transmissions over a payload channel from ready nodes in the clear to transmit state after more than one iteration of the determining and selectively sending steps.