Automated tool method for frequency plan revision within a cellular telephone system

• US 6,212,386 B1
• Filed: 06/30/1998
• Issued: 04/03/2001
• Est. Priority Date: 06/30/1998
• Status: Expired due to Term

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Guimont, Vincent, Karlsson, Patrik, Dufour, Daniel, Briere, Sylvain, Bringby, Daniel
• Primary Examiner(s): VO, NGUYEN THANH
• Application Number:
  US09/108,523
• Time in Patent Office: 1,008 Days
• Field of Search: 455/423, 455/424, 455/425, 455/446, 455/434, 455/450, 455/452, 455/62, 455/552, 455/553, 455/67.1, 455/8, 455/9, 455/509, 455/447
• US Class Current: 455/447
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

Interference and bit error rate measurements are made on the uplink and downlink to determine communications quality. Mobile station mobile assisted hand-off (MAHO) functionality is utilized to make the downlink measurements. Following filtering, the measurements are evaluated to identify potential candidates for reallocation. In one type of evaluation, when measured downlink bit error rate on a selected frequency is lower than a threshold and is worse than measured uplink bit error rate, then a better quality candidate is chosen to replace the selected frequency. In another type of evaluation, when a best available candidate has better interference than a worst quality one of the selected frequencies, that best candidate is chosen to replace the selected frequency.

Claims

1. A method for automated and autonomous planning of a revision to a frequency plan assignment within a cellular communications system in response to a situation wherein a certain transceiver within a certain cell has been maintenance blocked as not operable, comprising the steps of:

marking, due to the maintenance block, of a certain frequency assigned to that certain transceiver in the certain cell;

evaluating communications quality within the cellular communications system;

selecting based on the evaluated communications quality a revision to the frequency plan assignment, wherein the step of selecting further includes the steps of;

checking for marked frequencies; and

preventing another cell of the system proximate to the certain cell from being reallocated use of the marked certain frequency assigned to that certain transceiver in the certain cell.

2. A method for automated and autonomous planning of a revision to a frequency plan assignment within a cellular communications system in a situation wherein a certain one of a plurality of transceivers within a certain cell is to be removed from operation, comprising the steps of:

evaluating communications quality within the cellular communications system with respect to frequencies currently allocated to the plurality of transceivers within the certain cell;

selecting based on the evaluated communications quality a revision to the frequency plan assignment, wherein the step of selecting further includes the steps of;

identifying a to be retained one of the plurality of transceivers allocated a frequency with an evaluated communications quality worse than an evaluated communications quality of a frequency allocated to the certain one of the transceivers to be removed from operation; and

exchanging within the certain cell the allocated frequencies of the to be retained one of the plurality of transceivers and the certain one of the transceivers to be removed from operation.

3. A method for automated and autonomous planning of a revision to a frequency plan assignment within a cellular communications system in a situation wherein a new cell has been added to the cellular communications system, comprising the steps of:

evaluating communications quality within the cellular communications system with respect to sub-frequency groups currently allocated within the cellular communications system;

selecting based on the evaluated communications quality a revision to the frequency plan assignment, wherein the step of selecting further includes the steps of;

identifying candidate ones of the sub-frequency groups;

evaluating the candidate sub-frequency groups to identify a best candidate sub-frequency group;

validating the identified best candidate sub-frequency group; and

assigning frequencies within the validated best candidate sub-frequency group to transceivers within the recognized new cell.

4. The method as in claim 3 wherein the step of identifying candidate ones of the sub-frequency groups comprises the steps of:

identifying sub-frequency groups not selected for that cell; and

choosing those identified sub-frequency groups which are compatible with any existing selected sub-frequency groups for that cell.

5. The method as in claim 3 wherein the step of evaluating the candidate sub-frequency groups comprises the step of choosing a least uplink interfered one of the candidate sub-frequency groups.

6. The method as in claim 3 wherein the step of validating the identified best candidate sub-frequency group comprises the steps of:

confirming that the best candidate sub-frequency group is compatible with an existing frequency plan state of the communications system; and

confirming that the best candidate sub-frequency group is compatible with any currently pending proposals for revision to the existing frequency plan.

7. The method as in claim 3 further including the steps of:

determining whether all transceivers within the recognized new cell have been assigned frequencies; and

if not, repeating the step of selecting to assign additional frequencies to transceivers of the new cell.

8. The method as in claim 3 wherein the step of assigning frequencies comprises the step of assigning a least interfered one of the frequencies to the transceiver supporting a control channel for the new cell.

9. The method as in claim 3 wherein the step of assigning frequencies comprises the step of assigning a frequency tagged for control channel use to the transceiver supporting a control channel for the new cell.

10. A method for automated and autonomous planning of a revision to a frequency plan assignment within a cellular communications system in a situation wherein a new transceiver has been added to a cell of the cellular communications system, comprising the steps of:

evaluating communications quality within the cellular communications system with respect to sub-frequency groups currently allocated within the cellular communications system;

selecting based on the evaluated communications quality a revision to the frequency plan assignment, wherein the step of selecting further includes the steps of;

identifying candidate ones of the sub-frequency groups;

evaluating the candidate sub-frequency groups to identify a best candidate sub-frequency group;

validating the identified best candidate sub-frequency group; and

assigning frequencies within the validated best candidate sub-frequency group to the new transceiver.

11. The method as in claim 10 wherein the step of identifying qualified ones of the sub-frequency groups comprises the steps of:

identifying sub-frequency groups not selected for that cell; and

choosing those identified sub-frequency groups which are compatible with any existing selected sub-frequency groups for that cell.

12. The method as in claim 10 wherein the step of evaluating the qualified sub-frequency groups comprises the steps of:

choosing a least uplink and downlink interfered one of the candidate sub-frequency groups; and

if none, then choosing a least uplink interfered one of the candidate sub-frequency groups.

13. The method as in claim 10 wherein the step of validating the identified best qualified sub-frequency group comprises the steps of:

confirming that the best candidate sub-frequency group is compatible with an existing frequency plan state of the communications system; and

confirming that the best candidate sub-frequency group is compatible with any currently pending proposals for revision to the existing frequency plan.

14. The method as in claim 10 wherein the step of assigning frequencies comprises the step of assigning a least interfered one of the frequencies to the transceiver supporting a control channel for the new cell.

15. The method as in claim 10 wherein the step of assigning frequencies comprises the step of assigning a frequency tagged for control channel use to the transceiver supporting a control channel for the new cell.

16. A method for automated and autonomous planning of a revision to a frequency plan assignment within a cellular communications system, comprising the steps of:

evaluating communications quality within the cellular communications system with respect to sub-frequency groups currently allocated within the cellular communications system;

identifying a worst sub-frequency group associated with a certain cell;

selecting based on the evaluated communications quality a revision to the frequency plan assignment with respect to that certain cell, wherein the step of selecting further includes the steps of;

identifying a best candidate sub-frequency group;

validating the best candidate sub-frequency group; and

assigning frequencies within the validated best candidate sub-frequency group to each transceiver within the certain cell in order to replace the frequencies of the identified worst sub-frequency group associated with the certain cell.

17. The method as in claim 16 wherein the step of identifying a worst sub-frequency group comprises the step of identifying the certain cell having a worst interference condition.

18. The method as in claim 16 wherein the step of identifying the best candidate sub-frequency group comprises the step of choosing a least uplink and downlink interfered one of the candidate sub-frequency groups.

19. The method as in claim 16 wherein the step of validating the identified best candidate sub-frequency group comprises the steps of:

confirming that the best candidate sub-frequency group is compatible with an existing frequency plan state of the communications system; and

confirming that the best candidate sub-frequency group is compatible with any currently pending proposals for revision to the existing frequency plan.

20. The method as in claim 16 wherein the step of assigning frequencies comprises the step of assigning a least interfered one of the frequencies to the transceiver supporting a control channel for the new cell.

21. The method as in claim 16 wherein the step of assigning frequencies comprises the step of assigning a frequency tagged for control channel use to the transceiver supporting a control channel for the new cell.

22. The method as in claim 16 wherein the step of selecting the revision to the frequency plan assignment with respect to that certain cell gives independent consideration to both uplink and downlink in making revision selections such that:

the step of identifying a worst sub-frequency group comprises the step of identifying the certain cell having a worst downlink interference condition; and

if no certain cell having a worst downlink interference condition is identified, then the step of identifying a worst sub-frequency group comprises the step of identifying the certain cell having a worst uplink interference condition.

23. The method as in claim 22 wherein the step of selecting the revision by giving independent consideration to both uplink and downlink further comprises responding to identifying the certain cell having a worst downlink interference condition such that:

the step of identifying the best candidate sub-frequency group comprises the step of choosing a least downlink interfered one of the candidate sub-frequency groups; and

the step of validating the identified best candidate sub-frequency group comprises the steps of;

confirming that the best candidate sub-frequency group is compatible with an existing downlink frequency plan state of the communications system; and

confirming that the best candidate sub-frequency group is compatible with any currently pending proposals for revision to the existing downlink frequency plan.

24. The method as in claim 23 wherein the step of assigning frequencies comprises the step of assigning frequencies from the validated best candidate sub-frequency group for downlink transceiver use.

25. The method as in claim 22 wherein the step of selecting the revision by giving independent consideration to both uplink and downlink further comprises responding to identifying the certain cell having a worst uplink interference condition such that:

the step of identifying the best candidate sub-frequency group comprises the step of choosing a least uplink interfered one of the candidate sub-frequency groups; and

the step of validating the identified best candidate sub-frequency group comprises the steps of;

confirming that the best candidate sub-frequency group is compatible with an existing uplink frequency plan state of the communications system; and

confirming that the best candidate sub-frequency group is compatible with any currently pending proposals for revision to the existing uplink frequency plan.

26. The method as in claim 25 wherein the step of assigning frequencies comprises the step of assigning frequencies from the validated best candidate sub-frequency group for uplink transceiver use.

27. A method for planning a revision to a frequency plan assignment within a cellular communications system, comprising the steps of:

generating first proposals for revision to the frequency plan assignment in an open loop evaluation process which supports system operator consideration and input;

generating second proposals for revision to the frequency plan assignment in a closed loop evaluation process which is autonomous to and independent of system operator consideration and input;

choosing among the first and second proposals for implementation in revising the frequency plan assignment.

28. The method as in claim 27 wherein the step of choosing comprises the steps of:

selecting a first or second proposal for implementation;

considering a system effect of a first of second proposal selected for implementation on any subsequently generated first or second proposals.

29. The method as in claim 27 wherein the step of choosing comprises the step of giving priority to a first proposal over a second proposal.

30. The method as in claim 27 wherein the step of generating first proposals gives consideration to previously generated first and second proposals.

31. The method as in claim 27 wherein the step of generating second proposals gives consideration to previously generated first and second proposals.

32. A method for automated and autonomous planning of a revision to a frequency plan assignment within a cellular communications system, comprising the steps of:

determining whether a frequency set of a certain cell contains at least one frequency tagged for use as a digital control channel;

if yes, separately evaluating communications quality within the cellular communications system with respect to digital voice channel and digital control channel sub-frequency groups currently allocated within the cellular communications system in order to identify a potential best candidate digital voice channel and digital control channel sub-frequency group having frequencies suitable for assignment to transceivers within the certain cell in order to replace the frequencies of a digital voice channel and digital control channel, respectively, sub-frequency group currently associated with the certain cell; and

if no, evaluating communications quality within the cellular communications system with respect to digital voice channel sub-frequency groups currently allocated within the cellular communications system to identify a best candidate digital voice channel sub-frequency group having frequencies suitable for assignment to transceivers within the certain cell in order to replace the frequencies of a digital voice channel sub-frequency group currently associated with the certain cell.

33. The method as in claim 32 wherein the step of separately evaluating comprises the steps of:

identifying a worst digital voice channel sub-frequency group associated with the certain cell;

selecting based on the evaluated communications quality a best candidate digital voice channel sub-frequency group;

validating the best candidate digital voice channel sub-frequency group to identify frequencies for assignment to each transceiver within the certain cell in order to replace the frequencies of the identified worst digital voice channel sub-frequency group associated with the certain cell;

identifying a worst digital control channel sub-frequency group associated with the certain cell;

selecting based on the evaluated communications quality a best candidate digital control channel sub-frequency group; and

validating the best candidate digital control channel sub-frequency group to identify frequencies for assignment to each transceiver within the certain cell in order to replace the frequencies of the identified worst digital control channel sub-frequency group associated with the certain cell.

34. The method as in claim 33 further including the step of giving prioritization to the best candidate digital control channel sub-frequency group over the best candidate digital voice channel sub-frequency group in assigning frequencies for implementing the revision to the frequency plan assignment.

35. A method for automated and autonomous planning of a revision to a frequency plan assignment within a cellular communications system for a certain cell, comprising the steps of:

identifying a first list of sub-frequency groups characterized as being highly interfered on either an uplink or downlink;

identifying a second list of sub-frequency groups characterized as being currently assigned to a neighbor cell of the certain cell;

identifying a third list of sub-frequency groups characterized as being potential candidate sub-frequency groups for assignment to the certain cell in a revision to the frequency plan, provided that the third list does not include any of the sub-frequency groups contained in the first and second lists;

ordering mobile stations operating within the certain cell to make downlink interference measurements on frequencies comprising the sub-frequency groups contained in the third list;

selecting based on the uplink and downlink communications quality a best candidate sub-frequency group from the third list;

validating the best candidate digital voice channel sub-frequency group; and

assigning frequencies of the validated best candidate sub-frequency group to each transceiver within the certain cell.

36. The method as in claim 35 wherein the step of ordering comprises the step of taking into account traffic capacity in the certain cell in order to make a sufficient number of downlink interference measurements.

37. The method as in claim 35 wherein the step of ordering comprises the step of rotating through the sub-frequency groups within the third list in order to make downlink interference measurement over each of the included sub-frequency groups.

38. The method as in claim 35 further comprising the step of giving separate consideration to downlink measurement concerning digital control channels and digital voice channels, wherein the step of giving comprises:

the step of identifying the first list of sub-frequency groups comprising the step of identifying separate first list digital voice channel and digital control channel sub-frequency groups characterized as being highly interfered on either the uplink or downlink;

the step of identifying the second list of sub-frequency groups comprising the step of identifying separate second list digital voice channel and digital control channel sub-frequency groups characterized as being currently assigned to the neighbor cell of the certain cell;

the step of identifying the third list of sub-frequency groups comprising the step of identifying separate third list digital voice channel and digital control channel sub-frequency groups characterized as being potential candidate digital voice channel and digital control channel, respectively, sub-frequency groups for assignment to the certain cell in a revision to the frequency plan, provided that the third list does not include any of the sub-frequency groups contained in the first and second lists; and

the step of ordering mobile stations operating within the certain cell to make downlink interference measurements comprises the step of ordering the mobile station to make downlink measurements on both digital voice channel and digital control channel frequencies comprising the sub-frequency groups contained in the third list.

39. The method as in claim 38 wherein the step of ordering further comprises the step of sharing mobile station downlink interference measurement capacity between making downlink measurements on digital voice channel and digital control channel frequencies comprising the sub-frequency groups contained in the third list.