Method for setting and adjusting a parameter dependent on a round trip time

Patent metadata

Field	Value
Publication number	US-9019854-B2
Application number	US-201013642645-A
Country	US
Kind code	B2
Filing date	Apr 26, 2010
Priority date	Apr 26, 2010
Publication date	Apr 28, 2015
Grant date	Apr 28, 2015

Abstract

An arrangement ( 17 ) is provided for setting and adjusting at least one parameter in a radio communication network ( 11 ), which is used in control of communication in the radio communication network and which is dependent on a round trip time for a signal travelling from a radio network controller ( 13 ) to a user equipment ( 16 ) and back to the radio network controller. The arrangement comprises a module ( 17 a ) for initially estimating a maximum value of the round trip time; a setting module ( 17 b ) for initially setting the parameter depending on the initially estimated maximum value of the round trip time; a module ( 17 c ) for measuring the round trip time; and a module ( 17 d ) for adjusting the parameter depending on the measured round trip time, wherein the measured round trip time is expected to be shorter than the initially estimated maximum value of the round trip time.

First claim

The invention claimed is:

1. An arrangement for setting and adjusting at least one parameter in a WCDMA (Wideband CDMA) radio communication network, said at least one parameter being used in control of communication in said radio communication network and being dependent on a round trip time for a signal travelling from a radio network controller to a user equipment and back to said radio network controller, said arrangement comprising:
an estimating module configured to initially estimate a maximum value of the round trip time;
a setting module configured to initially set said at least one parameter depending on the initially estimated maximum value of the round trip time;
a measuring module configured to measure the round trip time; and
an adjusting module configured to adjust said at least one parameter depending on the measured round trip time, wherein the measured round trip time is expected to be shorter than the initially estimated maximum value of the round trip time,
wherein said measuring module is configured to measure the round trip time by:
sending an NSCF (Node Synchronization Control frame) from said radio network controller to a radio base station connected to the radio network controller, and via which said user equipment is connected;
receiving in said radio network controller a response NSCF to said sent NSCF from said radio base station;
determining a round trip time for a signal travelling from said radio network controller to said radio base station and back to said radio network controller based on a time at which said NSCF was sent and the time at which said response NSCF was received;
estimating a fixed round trip time for a signal travelling from said radio base station to said user equipment and back to said radio base station; and
calculating the round trip time for said signal travelling from said radio network controller to said user equipment and back to said radio network controller as a sum of the determined round trip time for said signal travelling from said radio network controller to said radio base station and back to said radio network controller and the fixed round trip time for said signal travelling from said radio base station to said user equipment and back to said radio base station.

2. The arrangement of claim 1 , wherein said measuring module is configured to measure the round trip time by:
gradually decreasing the initially estimated maximum value of the round trip time;
repeatedly setting said at least one parameter depending on the gradually decreased maximum value;
using said repeatedly set parameter for control of the communication in said radio communication network;
monitoring a quality parameter of the communication in said radio communication network; and
determining the round trip time based on said repeatedly set parameter and the monitored
quality parameter of the communication in said radio communication network.

3. The arrangement of claim 1 , wherein said measuring module is configured to measure the round trip time by:
sending a query from said radio network controller to said user equipment;
receiving in said radio network controller a response to said query from said user equipment; and
determining the round trip time based on the time at which said query was sent and the time at which said response was received.

4. The arrangement of claim 3 , wherein the arrangement is configured to set and adjust said at least one parameter in a Wideband CDMA (WCDMA) radio communication network, wherein said query is a polling RLC (Radio Link Control) PDU (Protocol Data Unit) and said response is a status report, ACK (Acknowledgement of reception) or NACK (Negative Acknowledgement of reception), triggered by the polling RLC PDU.

5. The arrangement of claim 4 , wherein said polling RLC PDU has a sequence number higher or lower than the RLC window.

6. The arrangement of claim 1 , wherein said measuring module is configured to estimate the fixed round trip time for a signal travelling from said radio base station to said user equipment and back to said radio base station based on TTIDL (Transmission Time Interval Downlink), TTIUL (Transmission Time Interval Uplink), TTI alignment DL, TTI alignment UL, jitter delay, processing delay in user equipment, and HARQ (Hybrid Automatic Repeat Request) delay.

7. The arrangement of claim 1 , wherein said measuring module is configured to:
measure the round trip time repeatedly during a communication between a radio network controller and a user equipment; and
adjust said at least one parameter depending on the repeatedly measured round trip time.

8. The arrangement of claim 1 , wherein the arrangement comprises part of said radio network controller that is configured to connect to a radio base station via a satellite link, said radio base station in turn being connected to said user equipment.

9. A radio network controller comprising an arrangement for setting and adjusting at least one parameter in a WCDMA (Wideband CDMA) radio communication network, said at least one parameter being used in control of communication in said radio communication network and being dependent on a round trip time for a signal travelling from the radio network controller to a user equipment and back to said radio network controller, and said arrangement comprising:
an estimating module configured to initially-estimate a maximum value of the round trip time;
a setting module configured to initially set said at least one parameter depending on the initially estimated maximum value of the round trip time;
a measuring module configured to measure the round trip time; and
an adjusting module configured to adjust said at least one parameter depending on the measured round trip time, wherein the measured round trip time is expected to be shorter than the initially estimated maximum value of the round trip time,
wherein said measuring module is configured to measure the round trip time by:
sending an NSCF (Node Synchronization Control frame) from said radio network controller to a radio base station connected to the radio network controller, and via which said user equipment is connected;
receiving in said radio network controller a response NSCF to said sent NSCF from said radio base station;
determining a round trip time for a signal travelling from said radio network controller to said radio base station and back to said radio network controller based on a time at which said NSCF was sent and the time at which said response NSCF was received;
estimating a fixed round trip time for a signal travelling from said radio base station to said user equipment and back to said radio base station; and
calculating the round trip time for said signal travelling from said radio network controller to said user equipment and back to said radio network controller as a sum of the determined round trip time for said signal travelling from said radio network controller to said radio base station and back to said radio network controller and the fixed round trip time for said signal travelling from said radio base station to said user equipment and back to said radio base station.

10. A method for setting and adjusting at least one parameter in a WCDMA (Wideband CDMA) radio communication network, said at least one parameter being used for control in communication in said radio communication network and being dependent on a round trip time for a signal travelling from a radio network controller to a user equipment and back to said radio network controller, said method comprising:
initially estimating a maximum value of the round trip time;
initially setting said at least one parameter depending on the initially estimated maximum value of the

Assignees

• Jonsson Anders
• Lidian Namir
• Sun Louise
• Ericsson Telefon Ab L M

Inventors

• Jonsson Anders
• Lidian Namir
• Sun Louise

Classifications

• H04W92/04

  Interfaces between hierarchically different network devices · CPC title

• H04W56/0055

  determining timing error of reception due to propagation delay · CPC title

• H04L41/0816

  the condition being an adaptation, e.g. in response to network events · CPC title

• H04L43/0864 Primary

  Round trip delays · CPC title

• H04W56/0045

  compensating for timing error by altering transmission time · CPC title