Methods and Arrangements for Estimating Uplink Coverage in Wireless Communication Networks with Dynamic Cell Coverage

• US 20080310322A1
• Filed: 12/22/2004
• Published: 12/18/2008
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Tidestav, Claes
• Granted Patent: US 8,073,456 B2
• Time in Patent Office: Days
• US Class Current: 370/253
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic

Abstract

The present invention relates to methods and arrangements in cellular communication networks exhibiting dynamic cell coverage, in particular, to estimate the uplink coverage in a network in operation. According to the method of the present invention a received rate is determined from at least one mobile terminal being in a communication session, by measuring the number of received transport blocks during a predetermined time interval. The received rate is compared with a predetermined expected rate, and if the received rate is below the expected rate poor coverage is identified. Since the coverage is potentially load dependent an estimate of the uplink coverage has been obtained.

Claims

1. A method for estimating uplink coverage in a wireless communication system, the wireless communication system possibly exhibiting load dependent cell coverage, wherein the method gather traffic statistics related to radio coverage in individual cells in a wireless communication system in operation, characterised in that the method comprises the steps of:

determining a received rate from at least one mobile terminal being in a communication session, by measuring the number of received transport blocks during a predetermined time interval; and

comparing the received rate with a predetermined expected rate, and if the received rate is below the expected rate, identifying a possible uplink load dependent effect on the cell coverage.

2. The method according to claim 1, further comprising the step of:

storing an indication of insufficient coverage if the received rate is below the expected rate and/or storing the received rate if the received rate is below the expected rate.

3. The method according to claim 2, further comprising the step of:

performing a cell planning function using the stored indications on insufficient coverage and/or the stored received rates to identify areas with poor radio coverage.

4. The method according to claim 2, further comprising the steps of:

performing a load control function on the stored information to identify inadequate admission control thresholds by comparing the number of indications of insufficient coverage, or a ratio of transmission giving rise to indications of insufficient coverage compared to the total number of transmissions, with a predetermined load value, said load control function performed per cell;

suggesting a lowering of the admission control threshold if the load control function has identified an inadequate admission control threshold for the cell.

5. The method according to claim 2, further comprising the steps of:

performing a cell planning function using the stored indications on insufficient coverage and/or the stored received rates to identify areas with poor radio coverage;

performing a load control function on the stored information to identify inadequate admission control thresholds by comparing the number of indications of insufficient coverage, or a ratio of transmission giving rise to indications of insufficient coverage compared to the total number of transmissions, with a predetermined load value, said load control function performed per cell; and

suggesting a lowering of the admission control threshold if the load control function has identified an inadequate admission control threshold for the cell.

6. The method according to claim 2, wherein the step of comparing comprises the substeps of:

comparing the received rate of a first TTI and the received rate of a second consecutive TTI with the expected rate;

determining if the received rate of the second TTI is zero, and storing an indication of insufficient coverage and/or the received rate only if the received rate of both the first and second TTI are below the expected rate and the rate of the second TTI is nonzero, whereby discerning between low received rate due an ending transmission and low received rate possibly due to poor coverage.

7. The method according to claim 2, wherein in the comparing step the received rate is stored, and in the a cell planning function the stored received rates are analyzed to give an estimate of the coverage to be expected for a specific transmission rate, by ascribing the ratio of the transmissions that exhibit the specific transmission rate as the ratio of the cell that exhibit the specific transmission rate.

8. A method in a radio network controlling node in a wireless communication system, the wireless communication system possibly exhibiting load dependent cell coverage, wherein the method gather traffic statistics related to radio coverage in individual cells in a wireless communication system in operation, characterised in that the method comprises the steps of:

determining a received rate from at least one mobile terminal being in a communication session, by measuring the number of received transport blocks during a predetermined time interval;

comparing the received rate with a predetermined expected rate, and if the received rate is below the expected rate, identifying a possible uplink load dependent effect on the cell coverage; and

storing an indication of insufficient coverage if the received rate is below the expected rate and/or storing the received rate if the received rate is below the expected rate.

9. The method according to claim 8, wherein stored indications of insufficient coverage from a plurality of transmissions are used for radio resource management.

10. The method according to claim 9, further comprising the steps of:

performing a load control function on the stored information to identify inadequate admission control thresholds by comparing the number of indications of insufficient coverage, or a ratio of transmission giving rise to indications of insufficient coverage compared to the total number of transmissions, with a predetermined load value, said load control function performed per cell; and

suggesting a lowering of the admission control threshold if the load control function has identified an inadequate admission control threshold for the cell.

11. The method according to claim 8, wherein the step of comparing comprises the substeps of:

comparing the received rate of a first TTI and the received rate of a second consecutive TTI with the expected rate;

determining if the received rate of the second TTI is zero, and storing an indication of insufficient coverage and/or the received rate only if the received rate of both the first and second TTI are below the expected rate and the rate of the second TTI is nonzero, whereby discerning between low received rate due an ending transmission and low received rate possibly due to poor coverage.

12. A radio network controller adapted for use in a wireless communication system, the wireless communication system possibly exhibiting load dependent cell coverage, characterized by:

rate measuring means adapted to determine a received rate from at least one mobile terminal being in a communication session, said measuring means arranged to measure the number of received transport blocks during a predetermined time interval;

comparing means in connection with the rate measuring means, and adapted to compare the received rate with a predetermined expected rate; and

storing means in connection with the comparing means, and adapted to store an indication of insufficient coverage and/or the received rate, if the comparing means has found the received rate to be below the expected rate.

13. The radio network controller according to claim 12, the radio network controller utilizing admission control, further provided with load control means in connection with the storing means, and adapted to compare the number of indications of insufficient coverage, or a ratio of transmission giving rise to indications of insufficient coverage compared to the total number of transmissions, with a predetermined load value and output a suggestion of a lowering of the admission control threshold if the number of indications of insufficient coverage, or a ratio of transmission giving rise to indications of insufficient coverage compared to the total number of transmissions is below the predetermined load value.

14. A system comprising of a radio network controller and an operation and a management node adapted for use in a wireless communication system, the wireless communication system possibly exhibiting load dependent cell coverage, characterized by:

rate measuring means adapted to determine a received rate from at least one mobile terminal being in a communication session, said measuring means arranged to measure the number of received transport blocks during a predetermined time interval;

comparing means in connection with the rate measuring means, and adapted to compare the received rate with a predetermined expected rate; and

storing means in connection with the comparing means, and adapted to store an indication of insufficient coverage and/or the received rate, if the comparing means has found the received rate to be below the expected rate, and the operation and management node is provided with analyzing means adapted to retrieve the stored indications of insufficient coverage and/or the received rates from the storing means of the radio network controller and identify cells with poor coverage by comparing the number of indications of insufficient coverage with the total number of transmissions.