Method and apparatus for initializing a packet traffic channel in a communication system

• US 6,717,916 B1
• Filed: 07/14/1998
• Issued: 04/06/2004
• Est. Priority Date: 07/25/1997
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Yoon, Soon-Young, Kang, Hee-Won, Kim, Young-Ky, Ahn, Jae-Min
• Primary Examiner(s): Hsu, Alpus H.
• Assistant Examiner(s): Nguyen, Toan D.
• Application Number:
  US09/115,499
• Time in Patent Office: 2,093 Days
• Field of Search: 370/320, 370/322, 370/324, 370/328, 370/335, 370/341, 370/342, 370/441, 370/457, 370/311, 370/252, 370/253, 370/349, 370/350, 455/13.4, 455/38.3, 455/343, 455/522
• US Class Current: 370/252
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 8/24 Transfer of terminal data

Abstract

A method of initializing a packet traffic channel in a communication system to efficiently use channel capacity in a packet data service and to reduce time and power required to initialize a packet traffic channel includes timing alignment between a terminal and a base station, controlled access collision between terminals, use of preamble patterns, and a comb-type correlator branch.

Claims

1. A method of initializing a packet traffic channel for synchronizing packet traffic channels between a base station and a mobile station at a state transition from a packet idle state to a packet busy state in a mobile communication system wherein the base station has a forward packet traffic channel and a packet traffic control channel and the mobile station has a reverse packet channel, and the base station transmits a packet control message for assigning time slots of the forward or the reverse packet traffic channel via a packet control channel when generating packet data to be communicated with a specific mobile station in the packet idle state, the base station and the mobile station transition to the packet busy state by occupying the forward or the reverse packet traffic channel in an assigned time slot and communicating the packet data via the occupied time slot of the forward or the reverse packet traffic channel between the base station, and then the mobile station and the base station transition to the packet idle state, comprising the steps of:

(a) measuring and storing a delay time of a forward channel signal transmitted from the base station to the mobile station, and reporting the delay time to the base station in order to synchronize the timing of the mobile station to the timing of the base station, in the packet idle state after a call set up;

(b) controlling access collision between mobile stations attempting to access a base station by assigning a specific time slot to each mobile station in an access attempt, and causing the mobile station to access in the assigned time slot;

(c) achieving mobile acquisition rapidly by repeatedly using short preamble patterns for mobile stations; and

(d) performing power control on the packet traffic channel by adding correlation values in a search window of the specific time slot.

2. The method of claim 1, wherein step (a) further comprises reporting the delay to the base station in response to a reporting time period signal received from the base station.

3. The method of claim 1, wherein step (a) further comprises determining when the delay time exceeds a delay time initially set by the base station and the mobile station by a predetermined threshold.

4. The method of claim 3, further comprising the steps of:

storing an initial delay time;

calculating a delay time difference signal by subtracting the delay time from the initial delay time;

comparing the delay time difference signal to a threshold value; and

reporting the delay time if the delay time difference is larger than the threshold value.

5. The method of claim 4, further comprising the step of updating the initial delay time if the delay time difference signal exceeds the threshold value.

6. The method of claim 1, wherein step (b) further comprises the base station providing an access permission message to the mobile station for enabling the mobile station to access the base station.

7. The method of claim 1, wherein step (c) further comprises using Barker codes.

8. The method of claim 1, wherein step (d) further comprises:

receiving a signal from the base station;

detecting the correlation values in response to correlation position designating signals;

comparing the correlation values to a threshold value;

if a correlation value is greater than the threshold value, outputting a respective correlation value;

adding the respective correlation values; and

comparing a sum of the added correlation values to a reference power value and generating a power control bit in response thereto.

9. The method of claim 8, wherein the power control bit serves to decrease power if the sum of the added correlation values is larger than the reference power value.

10. The method of claim 8, wherein the power control bit serves to increase the power if the sum of the added correlation values is smaller than the reference power value.

11. The method of claim 8, wherein the power control bit adjusts a cycle of a clock for controlling a power control bit generation period.

12. The method of claim 1, wherein step (b) further comprises the base station setting a time slot index for each mobile station corresponding to the time slot to which the mobile station is assigned to for access.

13. The method of claim 12, further comprising the steps of:

receiving the time slot index at the mobile station;

comparing the time slot index to a time slot index count; and

the mobile station attempting access when the time slot index count equals the time slot index.

14. An apparatus for initializing a packet traffic channel for synchronizing packet traffic channels between a base station and a mobile station at a state transition from a packet idle state to a packet busy state in a mobile communication system wherein the base station has a forward packet traffic channel and a packet traffic control channel and the mobile station has a reverse packet channel, and the base station transmits a packet control message for assigning time slots of the forward or the reverse packet traffic channel via a packet control channel when generating packet data to be communicated with a specific mobile station in the packet idle state, the base station and the mobile station transition to the packet busy state by occupying the forward or the reverse packet traffic channel in an assigned time slot and communicating the packet data via the occupied time slot of the forward or the reverse packet traffic channel between the base station, and then the mobile station and the base station transition to the packet idle state, the apparatus comprising:

means for measuring and storing a delay time of a forward channel signal transmitted from the base station to the mobile station, and reporting the delay time to the base station, and synchronizing the timing of the mobile station to the timing of the base station, in the packet idle state after a call set up;

means for controlling access collision between mobile stations attempting to access a base station by assigning a specific time slot to each mobile station in an access attempt and causing the mobile terminal to access in the assigned time slot;

means for achieving mobile acquisition rapidly by repeatedly using short preamble patterns for mobile stations; and

means for performing a power control on the packet traffic channel by adding correlation values in a search window of the specific time slot.

15. The apparatus of claim 14, wherein the reporting means further comprises means for reporting the delay to the base station in response to a reporting time period signal received from the base station.

16. The apparatus of claim 14, further comprising means for determining when the delay time exceeds a delay time initially set by the base station and the mobile station by a predetermined threshold.

17. The apparatus of claim 16, further comprising:

means for storing an initial delay time;

means for calculating a delay time difference signal by subtracting the delay time from the initial delay time;

means for comparing the delay time difference signal to a threshold value; and

means for reporting the delay time if the delay time difference is larger than the threshold value.

18. The apparatus of claim 17, further comprising means for updating the initial delay time if the delay time difference signal exceeds the threshold value.

19. The apparatus of claim 14, wherein the controlling means further comprises means for the base station to provide an access permission message to the mobile station for enabling the mobile station to access the base station.

20. The apparatus of claim 14, wherein the acquisition achieving means further comprises using Barker codes.

21. The apparatus of claim 14, wherein the power control performing means further comprises:

means for receiving a signal from the base station;

means for detecting the correlation values in response to correlation position designating signals;

means for comparing the correlation values to a threshold value;

means for outputting a respective correlation value if a correlation value is greater than the threshold value;

means for adding the respective correlation values; and

means for comparing a sum of the added correlation values to a reference power value and generating a power control bit in response thereto.

22. The apparatus of claim 21, wherein the power control bit serves to decrease power if the sum of the added correlation values is larger than the reference power value.

23. The apparatus of claim 21, wherein the power control bit serves to increase the power if the sum of the added correlation values is smaller than the reference power value.

24. The apparatus of claim 21, wherein the power control bit adjusts a cycle of a clock for controlling a power control bit generation period.

25. The apparatus of claim 14, wherein the controlling means further comprises means for setting, in the base station, a time slot index for each mobile station corresponding to the time slot to which the mobile station is assigned to for access.

26. The apparatus of claim 25, further comprising:

means for receiving the time slot index at the mobile station;

means for comparing the time slot index to a time slot index count; and

means for the mobile station to attempt access when the time slot index count equals the time slot index.