Relay device and method

• US 9,144,033 B2
• Filed: 08/09/2012
• Issued: 09/22/2015
• Est. Priority Date: 08/19/2011
• Status: Active Grant

• Current Assignee: InterDigital Patent Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: SCA IPLA Holdings Incorporated (Sony Group Corp.)
• Inventors: Speight, Timothy James, Piggin, Paul William
• Primary Examiner(s): Orgad, Edan
• Assistant Examiner(s): MAGLO, EMMANUEL K
• Application Number:
  US14/239,605
• Publication Number:
  US 20140161024A1
• Time in Patent Office: 1,139 Days
• Field of Search: 370/252, 370/329, 455/522
• US Class Current: 1/1
• CPC Class Codes: H04B 7/15 Active relay systems
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04B 7/204 Multiple access
• CPC Class Codes: H04L 67/303 Terminal profiles
• CPC Class Codes: H04W 4/70 Services for machine-to-machine communication [M2M] or machine type communication [MTC]
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/221 using past power control commands
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 56/005 compensating for timing error by adjustment in the receiver
• CPC Class Codes: H04W 72/0473 the resource being transmission power
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 74/004 in the uplink, i.e. towards network
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 84/047 using dedicated repeater stations

Abstract

A wireless communications system including a base station, a relay device, and a terminal device. The terminal device can transmit one or more first type access request messages to request uplink resources from the base station, and if no response to the first type access request messages is received from the base station, transmit a second type access request message. The base station is responsive to a first type access request message received from the terminal device to transmit an allocation of uplink resources to the terminal device. The relay device is responsive to a second type access request message received from the terminal device to transmit a relayed access request message to request the base station to allocate uplink resources to the terminal device. The base station is responsive to the relayed access request message to transmit an allocation of uplink resources to the terminal device.

Claims

1. A relay device for wirelessly relaying data from a terminal device to a base station, the relay device comprising:

a receiver; and

a transmitter, responsive to an access request message of a second type being received at the receiver from the terminal device to transmit a relayed access request message to the base station to request the base station to allocate uplink resources to the terminal device;

wherein

the access request message of the second type is transmitted by the terminal device if no response to a transmitted access request message of a first type is received from the base station;

the access request messages of the first type include Random Access Channel preambles selected from a first group of Random Access Channel preambles;

the access request messages of the second type include Random Access Channel preambles selected from a second group of Random Access Channel preambles, which are different from the first group of Random Access Channel preambles;

the base station is responsive to either an access request message of the first type received from the terminal device or the relayed access request message from the relay device to transmit an allocation of uplink resources to the terminal device;

the relay device is operable

to measure a received signal power of the access request message of the second type received from the terminal device; and

to set power control information in the relayed access request message for controlling a power level of a subsequent transmission from the terminal device to the relay device on the allocated uplink resources; and

the allocation of uplink resources transmitted from the base station to the terminal device comprises the power control information for controlling the transmission power of the subsequent transmission from the terminal device to the relay device.

2. A relay device according to claim 1, wherein

the terminal device is operable to transmit uplink data to the relay device on the allocated uplink resources;

and

the relay device is operable to relay to the base station the uplink data received from the terminal device.

3. A relay device according to claim 1, wherein

the relay device is operable to determine an identifier for the terminal device from which the access request message of the second type was received and include the identifier in the relayed access request message transmitted to the base station;

and

the base station uses the identifier to transmit an allocation of uplink resources to the terminal device.

4. A relay device according to claim 1, wherein the power control information specifies a power offset from the received signal power of the access request message of the second type.

5. A relay device according to claim 1, wherein

the relay device is operable

to measure a propagation time delay between the terminal device and the relay device of the access request message of the second type;

to determine, based on the propagation time delay, a required timing advance offset for a subsequent transmission from the terminal device to the relay device so that a receive time of the subsequent transmissions at the relay device is synchronised with a receive time of transmissions from other terminal devices; and

to specify said timing advance offset in the relayed access request message.

6. A relay device according to claim 1, wherein the relayed access request message comprises an identification of the terminal device which transmitted the message.

7. A relay device according to claim 1, wherein

the relay device is responsive to an access request message of the second type received from the terminal device to request the base station to allocate uplink resources to the relay device to transmit the relayed access request message;

the base station is responsive to the request from the base station to allocate uplink resources to the relay device; and

the relay device is operable to transmit the relayed access request message to the base station using the uplink resources allocated to the relay device by the base station.

8. A relay device according to claim 1, wherein

the relay device is responsive to the uplink data received from the terminal device to request the base station to allocate uplink resources to the relay device to transmit the relayed uplink data;

the base station is responsive to the request from the base station to allocate uplink resources to the relay device; and

the relay device is operable to transmit the relayed uplink data to the base station using the uplink resources allocated to the relay device by the base station.

9. A relay device according to claim 2, wherein

the allocation of uplink resources transmitted from the base station to the terminal device is a Random Access Response;

and

the uplink data transmitted by the terminal device on the allocated uplink resources is a Message 3.

10. A relay device according to claim 2, wherein the uplink data comprises one or both of control information and data.

11. A relay device according to claim 2, wherein

the relay device is operable

to measure a received signal power of the uplink data received from the terminal device;

and

to set power control information in the relayed uplink data for controlling a power level of a subsequent transmission from the terminal device to the relay device.

12. A relay device according to claim 2, wherein

the relay device is operable

to measure a propagation time delay between the terminal device and the relay device of the uplink data;

to determine, based on the propagation time delay, a required timing advance offset for a subsequent transmission from the terminal device to the relay device so that a receive time of the subsequent transmission at the relay device is synchronised with a receive time of transmissions from other terminal devices; and

to specify said timing advance offset in the relayed uplink data.

13. A relay device according to claim 2, wherein the relayed uplink data comprises an identification of the terminal device which transmitted the uplink data.

14. A relay device according to claim 3, wherein

the access request messages are transmitted on a random access channel;

and

the relay device is operable to determine an identifier for the terminal device from the time and/or frequency resource within the random access channel used to transmit the access request message of the second type.

15. A relay device according to claim 5, wherein the allocation of uplink resources transmitted from the base station to the terminal device comprises the timing advance offset for controlling the timing of a subsequent transmission from the terminal device to the relay device.

16. A terminal device for wirelessly communicating data to a base station via a relay device, the terminal device comprising:

a transmitter operable to transmit one or more access request messages of a first type to request uplink resources from the base station, and

if no response to the transmitted access request messages of the first type is received from the base station, to transmit an access request message of a second type; and

a receiver operable to receive from the base station an allocation of uplink resources allocated at the base station in response to one of an access request message of the first type or a relayed access request message transmitted to the base station by the relay device in response to an access request message of the second type being received from the terminal device, the relayed access request message requesting the base station to allocate uplink resources to the terminal device, wherein

the access request messages of the first type include Random Access Channel preambles selected from a first group of Random Access Channel preambles,

the access request messages of the second type include Random Access Channel preambles selected from a second group of Random Access Channel preambles, which are different from the first group of Random Access Channel preambles, wherein

the received allocation of uplink resources transmitted from the base station to the terminal device comprises power control information determined from a received signal power of the access request message of the second type received at the relay device; and

the terminal device transmits the uplink data at a power level specified by the power control information.

17. A terminal device according to claim 16, wherein

the terminal device is operable to transmit uplink data to the relay device on the allocated uplink resources;

and

the relay device is operable to relay to the base station the uplink data received from the terminal device.

18. A terminal device according to claim 16, wherein the terminal device is operable

to repeatedly transmit access request messages of the first type at successively higher power levels until a response is received from the base station or until a maximum power level is reached;

and

if no response to the access request message of the first type at the maximum power level is received from the base station, to transmit the access request message of the second type.

19. A terminal device according to claim 16, wherein the power control information specifies a power offset from the received signal power of the access request message of the second type received at the relay device.

20. A terminal device according to claim 17, wherein

the allocation of uplink resources transmitted from the base station to the terminal device is a Random Access Response;

and

the uplink data transmitted by the terminal device on the allocated uplink resources is a Message 3.

21. A terminal device according to claim 17, wherein the uplink data comprises one or both of control information and data.

22. A terminal device according to claim 17, wherein

the received allocation of uplink resources transmitted from the base station to the terminal device comprises a required timing advance offset for the terminal device to transmit to the relay device so that a receive time of the transmission at the relay device is synchronised with a receive time of transmissions from other terminal devices, the timing advance offset being determined at the relay device from a propagation time delay between the terminal device and the relay device of the access request message of the second type.

23. A terminal device according to claim 18, wherein the access request message of the second type is transmitted at the maximum power level.

24. A terminal device according to claim 18, wherein the maximum power level for transmitting the access request messages of the first type is less than the maximum transmission power of the terminal device.

25. A method of wirelessly relaying data from a terminal device to a base station by a relay device, comprising:

responsive to an access request message of the second type being received from the terminal device, transmitting a relayed access request message to the base station to request the base station to allocate uplink resources to the terminal device;

wherein

the access request message of the second type is transmitted by the terminal device if no response to the transmitted access request message of the first type is received from the base station;

the access request message of the first type includes Random Access Channel preambles selected from a first group of Random Access Channel preambles;

the access request message of the second type includes Random Access Channel preambles selected from a second group of Random Access Channel preambles, which are different from the first group of Random Access Channel preambles;

the base station is responsive to either an access request message of the first type received from the terminal device or the relayed access request message from the relay device to transmit an allocation of uplink resources to the terminal device;

the method further comprising measuring a received signal power of the access request message of the second type received from the terminal device; and

setting power control information in the relayed access request message for controlling a power level of a subsequent transmission from the terminal device to the relay device on the allocated uplink resources, wherein

the allocation of uplink resources transmitted from the base station to the terminal device comprises the power control information for controlling the transmission power of the subsequent transmission from the terminal device to the relay device.

26. A method of wirelessly communicating data from a terminal device to a base station via a relay device, comprising:

transmitting one or more access request messages of a first type to request uplink resources from the base station, and

if no response to the transmitted access request messages of the first type is received from the base station, transmitting an access request message of a second type; and

receiving from the base station an allocation of uplink resources allocated at the base station in response to one of an access request message of the first type or a relayed access request message transmitted to the base station by the relay device in response to an access request message of the second type being received from the terminal device, the relayed access request message requesting the base station to allocate uplink resources to the terminal device, wherein

the access request messages of the first type include Random Access Channel preambles selected from a first group of Random Access Channel preambles,

the access request messages of the second type include Random Access Channel preambles selected from a second group of Random Access Channel preambles, which are different from the first group of Random Access Channel preambles, wherein

the received allocation of uplink resources transmitted from the base station to the terminal device comprises power control information determined from a received signal power of the access request message of the second type received at the relay device; and

the terminal device transmits the uplink data at a power level specified by the power control information.