METHOD AND SYSTEM FOR SPEED ESTIMATION IN A NETWORK

Abstract

Estimating the speed of a mobile user terminal within a wireless environment and estimating the time when a mobile user terminal would reach a coverage border of the access point it is currently associated with. In particular, the present system is concerned with calculating a time (T) the terminal would take to move from a point A, after it has stopped making received signal level measurements, to another point B, at the coverage border of the access point, independently of any medium-specific parameters. This way, the present system enhances Quality of Service by properly estimating the speed and time and enabling a terminal, or an entity in the network, to take preemptive actions to ensure optimal QoS.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a mobile user terminal diagram, illustrating the implementation of an improved method and system according to one of the embodiments of the present system;

FIG. 2 is a graph illustrating the RSSI attenuation as a logarithmic function, according to one of the embodiments of the present system;

FIG. 3 is a flowchart of the improved method according to one of the embodiments of the present system;

FIG. 4 illustrates an implementation of the system according to the present system; FIG. 5 illustrates an implementation of the mobile user terminal according to the present system; and

FIG. 6 shows a mobile user terminal in accordance with an embodiment of the present system.

Claims

1. A method of estimating a speed of a mobile user terminal, said terminal being positioned at a first instant in a first point associated with at least one access point in a RF coverage radius, having a first distance between the first point and the at least one access point, wherein the user terminal has a trajectory, said terminal experiencing a received signal level along the trajectory, wherein the method comprises the acts of: performing periodic measurements of the received signal level of the terminal along the trajectory, wherein the received signal level comprises its strength indication;determining a second point along the trajectory, wherein the received signal level is a maximum of the periodic measurements; said second point corresponding to a second instant, andcomputing the speed of the mobile user terminal using the first distance, the strength indications at the first and second points and the time between the first and second instants.

2. The method of claim 1, wherein the act of computing the speed further comprises the acts of: estimating a second distance between the at least one access point and the second point along the trajectory of the terminal using the received signal level of the first point, the second point and the first distance,computing the distance between the first and second points based on the first and second distances, andcomputing the speed of the user terminal as the ratio of the distance between the first and second points and the time between the first and second instants.

3. The method of claim 2, wherein the trajectory is assumed to be a substantially straight trajectory, and in the act of computing the distance between the first and second points, said distance is calculated as: d=√{square root over (dc2−dM2)}

4. The method of claim 1, further comprising the act of calculating the time it takes from the moment the mobile user terminal has stopped performing signal measurements until the moment the mobile user terminal reaches the at least one coverage border of the access point, said time being given by the relation: T=2*TM−i*ΔT,

5. The method of claim 1, wherein the act of determining the second point further comprising the act of: analyzing the attenuation of the received signal level of the terminal along the trajectory using a mathematical series theory to determine the second point by determining whether the received signal level is increasing or decreasing.

6. The method of claim 1, wherein the act of computing the speed of the mobile user terminal comprises the act of: calculating the speed by the relation:

7. The method of claim 1, further comprising the act of transmitting the measured received signal level from the mobile user terminal to a wireless network component, said network component computing the speed of said mobile user terminal.

8. The method of claim 1, wherein the mobile user terminal computes the speed of said mobile user terminal.

9. A computer program product to be stored on a device and having a sequence of instructions stored thereon which, when executed by a microprocessor of the device, causes the microprocessor to estimate a speed of a mobile user terminal, said terminal being positioned at a first instant in a first point associated with at least one access point in a RF coverage radius, having a first distance between the first point and the at least one access point, wherein the user terminal has a trajectory, said terminal experiencing a received signal level along the trajectory, said sequences of instructions comprising: instructions to perform periodic measurements of the received signal level of the terminal along the trajectory, wherein the received signal level comprises its strength indication;instructions to determine a second point along the trajectory, wherein the received signal level is a maximum of the periodic measurements; said second point corresponding to a second instant, andinstructions to compute the speed of the mobile user terminal using the first distance, the strength indications at the first and second points and the time between the first and second instants.

10. The computer program product of claim 9, wherein the instructions to compute the speed further comprise: instructions to estimate a second distance between the at least one access point and the second point along the trajectory of the terminal using the received signal level of the first point, the second point and the first distance,instructions to compute the distance between the first and second points based on the first and second distances, andinstructions to compute the speed of the user terminal as the ratio of the distance between the first and second points and the time between the first and second instants.

11. The computer program product of claim 10, wherein the trajectory is assumed to be a substantially straight trajectory, and wherein the distance between the first and second points is calculated as: d=√{square root over (dc2−dM2)}

12. The computer program product of claim 9, further comprising the instructions to calculate the time it takes from the moment the mobile user terminal has stopped performing signal measurements until the moment the mobile user terminal reaches the at least one coverage border of the access point, said time being given by the relation: T=2*TM−i*ΔT,

13. The computer program product of claim 9, wherein the instructions to compute the speed of the mobile user terminal comprise instructions to calculate the speed by the relation:

14. A system configured to estimate a speed of a mobile user terminal, said terminal being positioned at a first instant in a first point associated with at least one access point in a RF coverage radius, having a first distance between the first point and the at least one access point, wherein said mobile user terminal has a trajectory, said terminal experiencing a received signal level along the trajectory, said mobile user terminal being configured to: perform periodic measurements of the received signal level of the terminal along the trajectory, wherein the received signal level comprises its strength indication;

15. The system of claim 14, wherein the mobile user terminal is configured to transmit the measurements of the received signal levels to the system module.

16. The system of claim 14, the system module is further configured to: estimate a second distance between the at least one access point and the second point along the trajectory of the terminal using the received signal level of the first point, the second point and the first distance,compute the distance between the first and second points based on the first and second distances, andcompute the speed of the user terminal as the ratio of the distance between the first and second points and the time between the first and second instants.

17. The system of claim 14, wherein the trajectory is assumed to be a substantially straight trajectory, and wherein the system module is further configured to compute the distance between the first and second points using the relation: d=√{square root over (dc2−dM2)}

18. The system of claim 14, wherein the system module is further configured to calculate the time it takes from the moment the mobile user terminal has stopped performing signal measurements until the moment the mobile user terminal reaches the at least one coverage border of the access point (T), said time being given by the relation: T=2*TM−i*ΔT,

19. The system of claim 14, wherein the system module is further configured to calculate the speed using the relation:

20. A mobile user terminal configured to estimate its speed, said mobile user terminal being positioned at a first instant in a first point associated with at least one access point in a RF coverage radius, having a first distance between the first point and the at least one access point, wherein said mobile user terminal has a trajectory, said mobile user terminal experiencing a received signal level along the trajectory, said mobile user terminal being configured to: perform periodic measurements of the received signal level of the terminal along the trajectory, wherein the received signal level comprises its strength indication;determine a second point along the trajectory, wherein the received signal level is a maximum of the periodic measurements; said second point corresponding to a second instant, andcompute the speed of the mobile user terminal using the first distance, the strength indications at the first and second points and the time between the first and second instants.

21. The terminal of claim 20, wherein said terminal is further configured to: estimate a second distance between the at least one access point and the second point along the trajectory of the terminal using the received signal level of the first point, the second point and the first distance,compute the distance between the first and second points based on the first and second distances, andcompute the speed of the user terminal as the ratio of the distance between the first and second points and the time between the first and second instants.

22. The terminal of claim 20, wherein the trajectory is assumed to be a substantially straight trajectory, and wherein said terminal is further configured to compute the distance between the first and second points using the relation: d=√{square root over (dc2−dM2)}

23. The terminal of claim 20, wherein said terminal is further configured to calculate the time it takes from the moment the mobile user terminal has stopped performing signal measurements until the moment the mobile user terminal reaches the at least one coverage border of the access point (T), said time being given by the relation: T=2*TM−i*ΔT,

24. The terminal of claim 20, wherein said terminal is further configured to calculate the speed using the relation: