Wireless communications system and method
View Patent ↗A wireless communications system includes a base station, a plurality of intermediate devices, and a terminal device. Downlink communications may be provided directly from the base station to the terminal device, including control signals which instruct the terminal device where to send uplink data. This enables the base station to directly control scheduling of uplink communications, and in particular to define an uplink route from the terminal device to the base station via one or more intermediate devices. Power is conserved at the terminal device on the uplink because a lower power transmission can be used which although insufficient to reach the base station can reach the intermediate device. The terminal device is not required to determine the uplink path itself and therefore does not require complex, expensive, and power consuming control logic.
1. An intermediate device for wirelessly relaying data within a wireless communications system, the intermediate device comprising:
a receiver configured to
wirelessly receive, from a base station in the wireless communications system, first intermediate control signals that identify a second intermediate device as a target device of the intermediate device to which the intermediate device is to transmit uplink signals intended for the base station; and
wirelessly receive the uplink signals from a third intermediate device; and
a transmitter configured to wirelessly transmit the uplink signals to the target device, wherein
the third intermediate device receives, from the base station, second intermediate control signals that are different the first intermediate control signals and that identify the intermediate device as a target device of the third intermediate device to which the third intermediate device transmits the uplink signals.
2. The intermediate device according to claim 1 , wherein
the receiver is further configured to receive scheduling information having a plurality of address fields, and
the plurality of address fields include a transmitter address field identifying the intermediate device and a receiver address field identifying a device to which the intermediate device is to direct uplink signals intended for the base station.
3. The intermediate device according to claim 2 , wherein the plurality of address fields include radio network temporary identifiers (RNTIs) specified on a physical downlink control channel (PDCCH) broadcast by the base station.
4. The intermediate device according to claim 1 , wherein the intermediate device is configured to wirelessly receive, from the base station, an indication that the intermediate device is required to receive the uplink signals.
5. The intermediate device according to claim 4 , wherein the indication specifies a radio resource at which the intermediate device can expect the uplink signals to be transmitted to the intermediate device by a terminal device or by the third intermediate device.
6. The intermediate device according to claim 1 , wherein the intermediate device is configured to
receive a beacon signal from one of the base station, another intermediate device and a terminal device,
generate a respective measure of the radio link quality between the intermediate device and the device from which the beacon signal was received using the received beacon signals, and
transmit the measure of radio link quality to the base station within the uplink signals.
7. The intermediate device according to claim 6 , wherein a transmission route from the terminal device to the base station via one or more of intermediate devices is determined according to the transmitted measures of radio link quality.
8. The intermediate device according to claim 6 , wherein the receiver is further configured to receive scheduling information that scheduling information specifies one or more of a transmission power, data rate, transmission frequency, transmission timeslot and number of resource blocks for the uplink signals.
9. The intermediate device according to claim 8 , wherein the scheduling information is set for each radio link based on the radio link quality measure reported for each radio link.
10. The intermediate device according to claim 1 , wherein the intermediate device is a machine type communication (MTC) device.
11. The intermediate device according to claim 1 , wherein the intermediate device is a relay.
12. The intermediate device according to claim 1 , wherein the intermediate device is a terminal device.
13. A method of wirelessly relaying data within a wireless communications system, the method comprising:
wirelessly receiving, by an intermediate device from a base station in the wireless communications system, first intermediate control signals that identify a second intermediate device as a target device of the intermediate device to which the intermediate device is to transmit uplink signals intended for the base station;
wirelessly receiving, by the intermediate device, the uplink signals from a third intermediate device;
wirelessly transmitting, by the intermediate device, the received uplink signals to the target device; and
wirelessly receiving, by the third intermediate device from the base station, second intermediate control signals that are different from the first intermediate control signals and that identify the intermediate device as a target device of the third intermediate device to which the third intermediate device transmits the uplink signals.
14. A relay device, comprising:
a transceiver configured to
receive uplink signals from a user equipment;
receive, from a base station, first control signals that instruct the relay device to transmit the uplink signals to a target relay device within transmission range of the base station; and
transmit the uplink signals to the target relay device, wherein
the target relay device receives the uplink signals from the relay device,
the target relay device receives second control signals from the base station, the second control signals being different from the first control signals and identifying a second target relay device to which the target relay device transmits the uplink signals, and
the second target relay device receives the uplink signals from the target relay device and transmits the uplink signals to the base station.
15. The relay device according to claim 14 , wherein the transceiver is further configured to
transmit a beacon,
receive a communication request from the user equipment after the user equipment enters range of the relay device and receives the beacon,
forward the connection request to the base station, and
authorize connection to the user equipment when the user equipment receives a connection grant message from the base station.
16. The relay device according to claim 14 , wherein
the transceiver is further configured to receive scheduling information having a plurality of address fields, and
the plurality of address fields include a transmitter address field identifying the relay device and a receiver address field identifying a device to which the relay device is to direct uplink signals intended for the base station.
17. The relay device according to claim 16 , wherein the plurality of address fields include radio network temporary identifiers specified on a physical downlink control channel broadcast by the base station.
18. The relay device according to claim 14 , wherein the relay device is configured to
receive a beacon signal from one of the base station, another relay device and the user equipment,
generate a respective measure of the radio link quality between the relay device and the device from which the beacon signal was received using the received beacon signals, and
transmit the measure of radio link quality to the base station within the uplink signals.
19. The relay device according to claim 18 , wherein a transmission route from the user equipment to the base station via one or more of relay devices is determined according to the transmitted measures of radio link quality.
20. The relay device according to claim 14 , wherein the relay device is a user equipment configured to operate in a mesh network.