Method of controlling access to resources of a radiocommunication network and base station for implementing the method

• US 20050026622A1
• Filed: 06/24/2004
• Published: 02/03/2005
• Est. Priority Date: 06/24/2003
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Georgeaux, Eric, Fauconnier, Denis
• Granted Patent: US 7,653,016 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 48/02 Access restriction performed under specific conditions
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A radio terminal is organized to send a first access signal then, when it receives a positive acknowledgement from a base station, a second access signal, resources of the communication network being allocated to the radio terminal after receipt of the said second access signal at the base station. At a base station, the first access signal sent by a radio terminal is received and the communication service requested by the terminal is detected therein. In conditional manner, depending on the detected communication service, a receive power of the first access signal is measured, the measured receive power is compared with a threshold, and the transmission of a positive acknowledgement of the first access signal to the radio terminal is inhibited, when the measured receive power is greater than the said threshold.

Claims

1. Method of controlling access of at least one radio terminal to resources of a radiocommunication network to implement a communication service, the radiocommunication network comprising at least one base station, the radio terminal being organized to send a first access signal then, when it receives a positive acknowledgement of the first access signal from a base station, a second access signal substantially longer than the said first access signal, resources of the communication network being allocated to the radio terminal after receipt of the said second access signal at the base station, the method comprising the following steps:

/a/ receiving at a base station the first access signal sent by a radio terminal;

/b/ detecting, from the first access signal, a communication service requested by the radio terminal;

and comprising at least some of the following steps, in conditional manner, according to the communication service detected;

/c/ measuring a receive power of the first access signal;

/d/ comparing the measured receive power with a threshold; and

/e/ inhibiting the transmission of a positive acknowledgement of the first access signal to the radio terminal, when the measured receive power is greater than the said threshold.

2. Method according to claim 1, wherein the first access signal and the second access signal are respectively a preamble and a main portion of one and the same access signal.

3. Method according to claim 1, wherein the inhibition of the transmission of a positive acknowledgement of the first access signal consists at least in the transmission of a negative acknowledgement to the radio terminal.

4. Method according to claim 1, wherein at least step /e/ is not executed if the detected communication service is an emergency call.

5. Method according to claim 1, wherein the first access signal is sent by the radio terminal along a partition of a partitioned random access channel, the said partition depending on the requested communication service, in which each partition of the random access channel is characterized by a set of respective access parameters, such as a transmit sub-channel of the random access channel and a signature contained in the first access signal.

6. Method according to claim 5, wherein the first access signal is sent by the radio terminal along a partition of the random access channel, based on a correspondence between at least the partitions of the random access channel and the requested communication service, the said correspondence being deduced from information broadcast by the base station.

7. Method according to claim 5, wherein the first access signal is sent by the radio terminal along an identified partition of the random access channel, when the requested communication service is an emergency call.

8. Method according to claim 5, wherein detection of the requested communication service comprises a detection of the partition of the random access channel along which the first access signal is sent by the radio terminal.

9. Method according to claim 8, wherein the threshold with which the measured receive power is compared depends on the detected partition of the random access channel along which the first access signal is sent by the radio terminal.

10. Base station of a radiocommunication network, comprising means for receiving and positively acknowledging a first access signal from a radio terminal requesting a communication service, and means for receiving a second access signal substantially longer than the said first access signal, resources of the communication network being allocated to the radio terminal after receipt of the said second access signal at the base station, the base station also comprising:

/a/ means for detecting, based on a first access signal received from a radio terminal, a communication service requested by the radio terminal;

/b/ means for measuring a receive power of the first access signal;

/c/ means for comparing the measured receive power with a threshold; and

/d/ means for inhibiting the transmission of a positive acknowledgement of the first access signal to the radio terminal, when the measured receive power is greater than the said threshold,

at least some of the means /b/, /c/, /d/ being implemented, in conditional manner, according to the communication service detected by the means /a/.

11. Base station according to claim 10, wherein the first access signal and the second access signal are respectively a preamble and a main portion of one and the same access signal.

12. Base station according to claim 10, wherein the means for inhibiting the transmission of a positive acknowledgement of the first access signal comprise means for transmitting a negative acknowledgement to the radio terminal.

13. Base station according to claim 10, wherein at least the means /d/ are not activated if the detected communication service is an emergency call.

14. Base station according to claim 10, wherein the first access signal is sent by the radio terminal along a partition of a partitioned random access channel, the said partition depending on the requested communication service, in which each partition of the random access channel is characterized by a set of respective access parameters, such as a transmission sub-channel of the random access channel and a signature contained in the first access signal, and in which the means for receiving the first access signal comprise means for detecting the said partition of the partitioned random access channel along which the first access signal is sent.

15. Base station according to claim 14, comprising means of broadcasting information, in which the first access signal is sent by the radio terminal along a partition of the random access channel, based on a correspondence between at least the partitions of the random access channel and the requested communication service, the said correspondence being deduced from the information broadcast by the base station.

16. Base station according to claim 14, wherein the first access signal is sent by the radio terminal along an identified partition of the random access channel, when the requested communication service is an emergency call.

17. Base station according to claim 14, wherein the means for detecting the requested communication service comprise means for detecting the partition of the random access channel along which the first access signal is sent by the radio terminal.

18. Base station according to claim 17, wherein the threshold used by the means for comparing the measured receive power with a threshold depends on the partition detected by the means for detecting the partition of the random access channel along which the first access signal is sent by the radio terminal.