Method for communicating and radio station therefor
The present invention relates to method for communicating between a primary station and a secondary station comprising (a) at the secondary station, upon arrival of a data packet to be transmitted to the primary station, buffering said data packet in a buffer, and transmitting to the primary station a request for an uplink transmission resource if a request condition is satisfied, said request condition being based on at least one previous grant of uplink transmission resource, (b) at the primary station, granting to the secondary station an uplink transmission resource to be used.
1. A method for communicating between a primary station and a secondary station comprising
(a) at the secondary station, upon arrival of a data packet to be transmitted to the primary station:
buffering said data packet in a buffer,
determining whether an uplink grant is available; and
when said uplink grant is determined to be not available;
transmitting to the primary station a request for an uplink transmission resource if a request condition is satisfied, said request condition being based on at least one previous grant of uplink transmission resource and on a time elapsed since a previous transmission of an indication of an amount of data contained in the buffer without receiving a grant for transmission,
(b) at the primary station, granting to the secondary station an uplink transmission resource to be used.
2. The method of claim 1 , wherein the request condition is satisfied if a time elapsed since the previous grant of resource is greater than a threshold.
3. The method of claim 1 , wherein the request condition is satisfied if an average time between previous grants of resource is greater than a threshold.
4. The method of claim 1 , wherein a quantity of resource allocated in the previous grant of resource is less than a threshold.
5. The method of claim 1 , wherein an average amount of resource allocated in a set of previous grants of resource is less than a threshold.
6. The method of claim 1 , wherein a total amount of resource allocated in a set of previous grants of resource is less than a threshold.
7. The method of claim 2 , wherein the threshold depends at least on a set of data characteristics of a data packet in the buffer.
8. The method of claim 7 , wherein the set of data characteristics comprises at least one of: an indication of data priority, Quality of Service parameters, an identity of a logical channel or group of logical channels to which the data packets are assigned, an amount of data in the buffer, an amount of data which arrived, a rate of arrival of data, and a time elapsed since a previous arrival of data.
9. The method of claim 2 , wherein the secondary station operates in a radio cell, and wherein a threshold is based on the time elapsed since the secondary station has started to operate in said radio cell.
10. The method of claim 2 , wherein the threshold depends at least on a time elapsed since the secondary station last transmitted a request for an uplink transmission resource.
11. The method of claim 2 , wherein the threshold depends at least on a time elapsed since the secondary station last transmitted a request for an uplink transmission resource corresponding to a specific amount of data and did not receive a corresponding grant of resource.
12. The method of claim 2 , wherein the threshold depends at least on a set of uplink channel characteristics.
13. The method of claim 12 , wherein the set of uplink channel characteristic comprises at least one of: an uplink channel quality, a transmission rate corresponding to the uplink channel quality, and an uplink transmission power.
14. The method of claim 12 , wherein the set of uplink channel characteristics is estimated based on characteristics related to a downlink channel.
15. A secondary station comprising
means for transmitting data to a primary station on an uplink channel,
means for buffering data packets to be transmitted to the primary station upon arrival of said data packets,
means for determining whether an uplink grant is available; and
when said uplink grant is determined to be not available;
means for requesting an uplink grant if a request condition is satisfied said request condition being based on at least one previous grant of uplink transmission resource and on a time elapsed since a previous transmission of an indication of an amount of data contained in the buffer without receiving a grant for transmission.
16. A system comprising:
at least one secondary station comprising:
means for transmitting data to a primary station on an uplink channel,
means for buffering data packets to be transmitted to the primary station upon arrival of said data packets,
means for determining whether an uplink grant is available; and
when said uplink grant is determined to be not available;
means for requesting an uplink grant if a request condition is satisfied, said request condition being based on at least one previous grant of uplink transmission resource and on a time elapsed since a previous transmission of an indication of an amount of data contained in the buffer without receiving a grant for transmission; and
a primary station, said primary station comprising:
means for granting to the secondary station an uplink transmission resource.