Base station for LTE (long term evolution)

Abstract

There is provided a base station which can prevent transmission of a Time Synchronisation Info IE (Information Element) from causing a procedure which the base station cannot execute. When the base station (10-1) according to the present invention receives Muting Pattern Information which does not contain a Muting Pattern Offset, the base station (10-1) decides that the Muting Pattern Offset requested in a former request has been accepted.

Claims

1. A base station comprising: a memory; and a processor configured to communicate with a node, wherein the base station receives Pattern Information that does not contain a Muting Pattern Offset, and decides that a Muting Pattern Offset, requested in a former request included in an eNB Configuration Transfer message sent to a Mobile Management Entity (MIME), has been accepted.

2. The base station according to claim 1, wherein the Muting Pattern Information is an information element that is transmitted by another base station and transferred by a MME.

3. The base station according to claim 1, wherein a value of a Muting Pattern Period contained in the Muting Pattern Information is not zero.

4. The base station according to claim 1, wherein the former request contains a Muting Pattern Period and the Muting Pattern Offset.

5. The base station according to claim 1, wherein the former request is a message for requesting Active Muting.

6. The base station according to claim 1, wherein the former request is a message that is sent from the base station.

7. A base station comprising: a memory; and a processor configured to communicate with a node, wherein the base station transmits a message for requesting Active Muting, receives Muting Pattern Information that does not contain a Muting Pattern Offset, and decides that a Muting Pattern Offset, requested in a former request included in an eNB Configuration Transfer message sent to a Mobile Management Entity (MIME), has been accepted.

8. The base station according to claim 7, wherein the message contains a Source Stratum Level IE.

9. The base station according to claim 7, wherein the message contains a Muting Pattern Period and a Muting Pattern Offset.

10. The base station according to claim 7, wherein the Muting Pattern Information is transmitted as a response to the message.

11. The base station according to claim 7, wherein the former request is the message for requesting Active Muting.

12. A base station comprising: a memory; and a processor configured to communicate with a node and transmit a request including a Muting Pattern Period and a Muting Pattern Offset to another base station, wherein the base station receives Muting Pattern Information that does not contain a Muting Pattern Offset after transmitting the request to the another base station, and decides that the Muting Pattern Offset, requested in the request included in an eNB Configuration Transfer message sent to a Mobile Management Entity (MME), has been accepted by the another base station.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a view illustrating a configuration example of a wireless communication system of LTE.

(2) FIG. 2 is a sequence diagram for explaining an example of a case A of muting procedure.

(3) FIG. 3 is a sequence diagram for explaining examples of cases B and C of the muting procedure.

(4) FIG. 4 is a sequence diagram for explaining an example of a case D of the muting procedure.

(5) FIG. 5 is a sequence diagram for explaining an example of a case E of the muting procedure.

(6) FIG. 6 is a view illustrating an example of a Muting Pattern Information IE according to the present embodiment.

(7) FIG. 7 is a view illustrating an example of the Muting Pattern Information IE according to the present embodiment.

(8) FIG. 8 is a view illustrating an example of a SON Configuration Transfer IE according to the present embodiment.

(9) FIG. 9 is a view illustrating an example of a SON Information IE according to the present embodiment.

(10) FIG. 10 is a block diagram illustrating a configuration example of an eNB according to the present embodiment.

DESCRIPTION OF EMBODIMENTS

(11) The embodiment of the present invention will be described below with reference to the drawings.

(12) The present embodiment employ the same entire configuration of a wireless communication system as that in FIG. 1, yet add new functions to an eNB (#1) 10-1, an eNB (#2) 10-2 and an eNB (#3) 10-3 to solve above problems 1 to 4. In the present embodiment, methods for solving the above problems 1 to 4 are as follows.

(13) (1) Method for Solving Problem 1

(14) The problem 1 is that, in a case B and a case C, when a Muting Pattern Period IE received in step 204 in FIG. 3 indicates a value other than “0”, if a Muting Pattern Offset IE is not present, the eNB (#1) 10-1 cannot decide how to make interpretation.

(15) (1-1) Solving Method 1

(16) The solving method 1 changes a Muting Pattern Information IE as illustrated in FIG. 6 (changed portions are underlined).

(17) In FIG. 6, under a condition that the Muting Pattern Period IE is other than 0 (“C-ifOtherThanZero”) in the Muting Pattern Information IE (i.e., a condition that a muting period is set), the Muting pattern Offset IE which represents an offset is always present. In this regard, “C-ifOtherThanZero” may be “C-ifNotZero”.

(18) When the Muting Pattern Period IE is other than 0, the eNB (#2) 10-2 or the eNB (#3) 10-3 transmits to the eNB (#1) 10-1 the Muting Pattern Information IE to which the Muting Pattern Offset IE is set. Hence, when the Muting Pattern Period IE is other than 0, the eNB (#1) 10-1 can process the Muting Pattern Information IE transmitted from the eNB (#2) 10-2 or the eNB (#3) 10-3. Meanwhile, when, although the Muting Pattern Period IE is other than 0, the eNB (#2) 10-2 or the eNB (#3) 10-3 transmits to the eNB (#1) 10-1 the Muting Pattern Information IE to which the Muting Pattern Offset IE is not set, the eNB (#1) 10-1 may process the Muting Pattern Information IE as Abnormal.

(19) In the example in FIG. 3, the Muting Pattern Information IE is transmitted from the eNB (#2) 10-2 in step 203, and is received by the eNB (#1) 10-1 in step 204.

(20) Consequently, when the Muting Pattern Period IE indicates a value other than “0”, the eNB (#1) 10-1 can expect that the Muting Pattern Offset IE is always present. When this condition, i.e., that, although the Muting Pattern Period IE is other than 0, the Muting Pattern Offset IE is not present occurs, the eNB (#1) 10-1 processes this condition as Abnormal.

(21) (1-2) Solving Method 2

(22) The solving method 2 changes the Muting Pattern Information IE as illustrated in FIG. 7 (a changed portion is underlined).

(23) FIG. 7 illustrates added processing in a case where the Muting Pattern Offset is not present.

(24) When the eNB (#1) 10-1 receives a SON Information IE containing a SON Information Reply IE containing the Muting Pattern Information IE as a reply to a muting request which is a former request, the eNB (#1) 10-1 uses the SON Information IE to perform over-the-air synchronisation by using network listening.

(25) In this case, when the Muting Pattern Offset IE is not present, the eNB (#1) 10-1 decides that an offset requested in the former request has been accepted.

(26) Consequently, when the Muting Pattern Period IE indicates a value other than “0”, even if the Muting Pattern Offset IE is not present, the eNB (#1) 10-1 can decide how to make interpretation.

(27) (2) Method for Solving Problem 2

(28) The problem 2 is that, in the case B and the case C, when the eNB (#2) 10-2 receives the muting request from the eNB (#1) 10-1 via a MME 20-1 in step 202 in FIG. 3 and then tries to make a response by a Time Synchronisation Info IE, a reception side (i.e., eNB (#1) 10-1) does not know a method for processing the Time Synchronisation Info IE, and therefore a procedure which cannot be executed occurs.

(29) To solve the problem 2, an abnormal condition is added in the present embodiment in preparation for a case where the eNB (#2) 10-2 receives the muting request from the eNB (#1) 10-1 (i.e., the eNB (#2) 10-2 receives the SON Information IE containing the SON Information Request IE to which “Activate Muting” is set), and transmits a response by the Time Synchronisation Info IE.

(30) Variation 1 of Abnormal Condition)

(31) When the eNB (#1) 10-1 receives the SON Information IE containing the SON Information Reply IE containing the Time Synchronisation Info IE as a reply to the muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Activate Muting” is set), the eNB (#1) 10-1 decides that this muting request has failed.

(32) Variation 2 of Abnormal Condition)

(33) When the eNB (#1) 10-1 receives the SON Information IE containing the SON Information Reply IE containing the Time Synchronisation Info IE as a reply to the muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Activate Muting” is set), the eNB (#1) 10-1 decides that this muting request has failed, and transmits an Error Indication message which represents an error to a MME 20-1 or 20-2.

(34) Variation 3 of Abnormal Condition)

(35) When the eNB (#1) 10-1 receives the SON Information IE containing the SON Information Reply IE containing the Time Synchronisation Info IE as a reply to the muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Activate Muting” is set), the eNB (#1) 10-1 ignores the Time Synchronisation Info IE.

(36) Variation 4 of Abnormal Condition)

(37) When the eNB (#1) 10-1 receives the SON Information IE containing the SON Information Reply IE containing the Time Synchronisation Info IE as a reply to the muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Activate Muting” is set), the eNB (#1) 10-1 decides that this muting request has failed, and transmits to the MME 20-1 or 20-2 an eNB CONFIGURATION TRANSFER message which contains the SON Information IE containing the SON Information Request IE to which the “Error Indication” representing an error is set, and in which an appropriate Cause value representing an error cause is set to a Cause IE.

(38) Consequently, when the eNB (#2) 10-2 transmits the Time Synchronisation Info IE, it is possible to prevent this transmission from causing a procedure which the eNB (#1) 10-1 cannot execute.

(39) (3) Method for Solving Problems 3 and 4

(40) The problem 3 is that, in the case D, when the eNB (#2) 10-2 receives a muting deactivate request from the eNB (#1) 10-1 via the MME 20-1 in step 302 in FIG. 4, and then tries to make a response by a message containing an option IE such as the Time Synchronisation Info IE, the reception side (i.e., eNB (#1) 10-1) does not know a method for processing this message and a relevant IE, and therefore a procedure which cannot be executed occurs.

(41) The problem 4 is that, in the case E, when the eNB (#1) 10-1 receives the muting deactivate request from the eNB (#2) 10-2 via the MME 20-1 in step 402 in FIG. 5, and then tries to make a response by the message containing an option IE such as the Time Synchronisation Info IE, the reception side (i.e., eNB (#2) 10-2) does not know the method for processing this message and a relevant IE, and therefore the procedure which cannot be executed occurs.

(42) To solve the problems 3 and 4, an abnormal condition is added in the present embodiment in preparation for a case where the eNB (#1) 10-1 (or eNB (#2) 10-2) receives the muting deviate request from the eNB (#2) 10-2 (or eNB (#1) 10-1) (i.e., the eNB (#1) 10-1 (or eNB (#2) 10-2) receives the SON Information IE containing the SON Information Request IE to which “Deactivate Muting” is set), and then transmits a response message containing the Time Synchronisation Info IE.

(43) Variation 1 of Abnormal Condition)

(44) When the eNB (#1) 10-1 and the eNB (#2) 10-2 receive the SON Information IE containing the SON Information Reply IE which can contain the Time Synchronisation Info IE as a reply to the deactivate muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Deactivate Muting” is set), the eNB (#1) 10-1 and the eNB (#2) 10-2 decide that this deactivate muting request has failed.

(45) Variation 2 of Abnormal Condition)

(46) When the eNB (#1) 10-1 and the eNB (#2) 10-2 receive the SON Information IE containing the SON Information Reply IE which can contain the Time Synchronisation Info IE as a reply to the deactivate muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Deactivate Muting” is set), the eNB (#1) 10-1 and the eNB (#2) 10-2 decide that this deactivate muting request has failed, and transmit the Error Indication message which represents an error to the MME 20-1 or 20-2.

(47) Variation 3 of Abnormal Condition)

(48) When the eNB (#1) 10-1 and the eNB (#2) 10-2 receive the SON Information IE containing the SON Information Reply IE which can contain the Time Synchronisation Info IE as a reply to the deactivate muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Deactivate Muting” is set), the eNB (#1) 10-1 and the eNB (#2) 10-2 ignore this response message or ignore the Time Synchronisation Info IE.

(49) Variation 4 of Abnormal Condition)

(50) When the eNB (#1) 10-1 and the eNB (#2) 10-2 receive the SON Information IE containing the SON Information Reply IE which can contain the Time Synchronisation Info IE as a reply to the deactivate muting request which is the former request (i.e., the SON Information IE in this former request contains the SON Information Request IE to which “Deactivate Muting” is set), the eNB (#1) 10-1 and the eNB (#2) 10-2 decide that this deactivate muting request has failed, and transmits to the MME 20-1 or 20-2 the eNB CONFIGURATION TRANSFER message which contains the SON Information IE containing the SON Information Request IE to which the “Error Indication” representing an error is set, and in which the appropriate Cause value representing the error cause is set to the Cause IE.

(51) Consequently, when the eNB (#1) 10-1 (or eNB (#2) 10-2) transmit the Time Synchronisation Info IE, it is possible to prevent this transmission from causing a procedure which the eNB (#2) 10-2 (or eNB (#1) 10-1) cannot execute.

(52) FIG. 8 illustrates an example of the SON Configuration Transfer IE in a case where the variation 4 of the abnormal condition according to the methods for solving the problems 2, 3 and 4 is realized, and FIG. 9 illustrates an example of the SON Information IE.

(53) Lastly, a configuration example of the eNB (#1) 10-1, the eNB (#2) 10-2 and the eNB (#3) 10-3 will be described. FIG. 10 is a block diagram illustrating the configuration example of the eNB (#1) 10-1. The eNB (#1) 10-1 illustrated in FIG. 10 includes a communication unit 11 and a control unit 12. The communication unit 11 performs processing of communicating with the MMEs 20-1 and 20-2, the eNB (#2) 10-2 and the eNB (#3) 10-3. The control unit 12 is connected to the communication unit 11, and realizes various functions of the eNB (#1) 10-1 by executing programs read from a memory which is not illustrated. The communication unit 11 and the control unit 12 can be realized by a processor. In this regard, the configurations of the eNB (#2) 10-2 and the eNB (#3) 10-3 are also the same as that of the eNB (#1) 10-1.

(54) The present invention has been described above with reference to the embodiment. However, the present invention is not limited to the above. Various changes which one of ordinary skill in the art can understand can be made to the configurations and the details of the present invention without departing from the scope of the invention.

(55) For example, eNBs communicate via a MME in the embodiment. However, the eNBs may directly communicate via an X2 interface.

(56) Further, the eNB (#1) 10-1 which establishes time synchronisation with the eNB (#3) 10-3 is a pico eNB. However, the eNB (#1) 10-1 may be a femto eNB or a HeNB (Home eNB).

(57) This application claims priority to Japanese Patent Application No. 2015-100153 filed on May 15, 2015, the entire contents of which are incorporated by reference herein.

REFERENCE SIGNS LIST

(58) 10-1 to 10-3 eNB

(59) 20-1, 20-2 MME

(60) 11 COMMUNICATION UNIT

(61) 12 CONTROL UNIT