Method for controlling transmitting power in base station transceiver subsystem

A method for controlling the transmitting power in a base station transceiver subsystem is provided. The method includes the steps of collecting and combining fault information from devices that provide factors affecting a call processing service, and determining the range of transceivers that should have blocked transmitting power based on the collected and combined fault information. The transmitting power of the determined range of transceivers is blocked by sending a message to a corresponding transceiver interface processor connected to each of a plurality of transceiver groups within the base station transceiver subsystem. The transmitting powers are normally transmitting by sending a message to the corresponding transceiver interface processor, when a fault ceases.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 The present invention relates to digital cellular systems and, more
 particularly, to a method for controlling the transmitting power in a base
 station transceiver subsystem.
 2. Description of the Related Art
 In a digital cellular system such as a CDMA (Code Division Multiple Access)
 system or a PCS (Personal Communication System), when a call processing
 service cannot be provided or such service is partially limited due to
 abnormal circumstances present in a base station transceiver subsystem,
 the normal transmission of a transmitting power results in interference
 with other normal systems. In such a circumstance, service quality as a
 whole is reduced.
 SUMMARY OF THE INVENTION
 It is an object of the present invention to provide a control method for
 blocking the normal transmitting power when a call processing service
 cannot be provided or such service is partially limited due to abnormal
 circumstances present in a base station transceiver subsystem
 It is another object of the present invention to provide a method for
 controlling the transmitting power in accordance with present operating
 conditions in a base station transceiver subsystem.
 According to one feature of the present invention, a method for controlling
 the transmitting power in a base station transceiver subsystem includes
 the steps of collecting and combining fault information from devices that
 provide factors affecting a call processing service, and determining the
 range of transceivers that should have blocked transmitting power based on
 the collected and combined fault information. The transmitting power of
 the determined range of transceivers is blocked by sending a message to a
 corresponding transceiver interface processor connected to each of a
 plurality of transceiver groups within the base station transceiver
 subsystem. The transmitting powers are normally transmitting by sending a
 message to the corresponding transceiver interface processor, when a fault
 ceases.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 In the following description, numerous specific details, such as the number
 of respective elements, buffer maps, etc., are set forth to provide a more
 thorough understanding of the present invention. It will be apparent,
 however, to one skilled in the art that the present invention may be
 practiced without these specific details.
 FIG. 1 is a block diagram of a base station transceiver subsystem (BTS) of
 a PCS or CDMA system. A BTS status handing executor (BSHX) 12 within a BTS
 control processor (BCP) 10 manages the state of the devices which comprise
 the BTS. A BTS fault management executor (BFMX) within BCP 10 manages the
 faults of the BTS. A BTS test unit (BTU) 20 tests the BTS. Channel element
 interface processors (CIPs) 28-0 through 28-n monitor channel elements
 (CEs) 30-0 through 30-n, digitally combine signals generated from channel
 elements 30-0 through 30-n, and convert the combined digital samples into
 analog signals. In an illustrative embodiment of the present invention,
 n=23 for both the CIPs and the CEs. A high speed interconnect processor
 assembly (HIPA) 18 is a communication network manager for managing a
 network of the BTS and maintaining a high capacity IPC node board assembly
 (HINA).
 In the illustrative embodiment of FIG. 1, six (6) transceiver interface
 processors (TIPs) 22-0 through 22-5 receive data from BCP 10 for
 generating a radio frequency (RF) in each of transceivers (XCVRs) 24-0
 through 24-5, respectively, and transmit the received data to the
 transceivers 24-0 through 24-5. Moreover, TIPs 22-0 through 22-5 transmit
 state information received from the respective transceivers 24-0 through
 24-5 to BCP 10. The 6 transceivers 24-0 through 24-5 receive information
 from TIPs 22-0 through 22-5, respectively, in order to adjust transceiver
 frequency and output, detect alarm information and report a status, and
 display the status through a display unit. According to the illustrative
 embodiment, transceivers 24-0 through 24-5 each have 5 transceivers
 XCVR(0) through XCVR(4) therein. Therefore, a total of 30 transceivers are
 utilized in the illustrative embodiment.
 A BTS communication interconnect network (BCIN) 26 transmits packet data
 between internal devices of the BTS, and between the BTS and a base
 station controller (BSC) 50, providing a path therebetween. According to
 the illustrative embodiment, a trunk having a maximum of 16 links is
 provided between the BTS and a call control processor (CCP) 52 of the BSC
 50.
 FIG. 2 illustrates a buffer structure for storing the state of the trunk
 between the BTS and the BSC 50. FIG. 3 illustrates a buffer structure for
 storing the state of a CIP. FIG. 4 illustrates a buffer structure for
 storing the state of an automatic gain controller (AGC). FIG. 5
 illustrates a buffer structure for storing a transmission power mode. The
 buffers illustrated in FIGS. 2 through 5 are contained in BCP 10 of the
 BTS.
 Referring to FIG. 2, the buffer has 16 regions designated "Link
 State_Inform[0]" through "Link State Inform[15]" for storing state
 information of the 16 links of the trunk. Each region includes a state
 flag field `state_flag`, a configuration status field `config_sts`, a
 block status field `block-sts`, and a test status field `test_sts`. If
 information in any one of the fields `config_sts`, `block_sts`, and
 `test_sts` is abnormal, then abnormal state flag information is stored in
 the `state_flag` field. If the information is all normal, then normal
 state flag information is stored in the `state_flag` field. The status of
 a link monitored from the HIPA 18 is stored in the `config_sts` field.
 Link blocking information caused by man-machine communication (MMC) is
 stored in the `block_sts` field. The state of a link tested from the CCP
 52 of the BSC 50 is stored in the `test_sts` field.
 The buffer indicated in FIG. 3 has 24 regions designated
 "Cip_State_Inform[0]" through "Cip_State_Inform[23]" for storing the state
 information of the 24 CIPs. Each region includes a state flag field
 `state_flag`, a keep-alive status field `ka_sts`, and an alarm status
 field `alarm_sts`. If information in any one of the fields `ka_sts` and
 `alarm_sts` is abnormal, then abnormal state information is stored in the
 `state_flag` field. If the information is all normal, then normal state
 information is stored in the `state_flag` field. Information of a
 keep-alive status is stored in the `ka_sts` field. The keep-alive status
 represents that BCP 10 periodically transmits a message to a corresponding
 CIP and the corresponding CIP responds thereto. Information indicating
 whether or not a fault is generated in a CIP is stored in the `alarm_sts`
 field.
 The buffer shown in FIG. 4 stores state information of an automatic gain
 controller (AGC) that is situated at a connection path from a transceiver
 to a CIP. The state of the AGC is sensed by each CIP. The buffer is
 divided according to sectors .alpha., .beta. and .gamma.. One cell has the
 sectors .alpha., .beta. and .gamma.. Each sector consists of 3 bytes
 (i.e., 24 bits). This buffer structure is indicated as cip_agc_alm[x][y]
 (where x is a sector .alpha., .beta. or .gamma., and y is 0, 1 or 2). The
 state information of the AGC sensed by the 24 CIPs is stored in each of
 the 24 bits. For example, in bit7 of the third byte of the sector .alpha.,
 the state information of the AGC sensed by the 24-th CIP (i.e., CIP 23) is
 stored.
 Referring to FIG. 5, a "reason" region of the buffer, shown on the left
 side of FIG. 5, has fields `blink`, `llink`, `cip[0]` through `cip[n]`,
 `agc[0][0]` through `agc[k][n]`, and `lna[0][0]` through `lna[k][n]`. The
 parameter k is obtained by subtracting 1 from the maximum number of
 sectors per BTS (the maximum number of sectors equals 3, corresponding to
 sectors .alpha., .beta. or .gamma.). The parameter n is obtained by
 subtracting 1 from the maximum number of CDMA channels (i.e., 8, as
 explained hereinbelow). One CDMA channel corresponds to one frequency
 allocator (FA). Since 3 CIPs are assigned by one FA, the 24 CIPs of the
 present invention are assigned by 8 FAs. Therefore, the maximum number of
 CDMA channels is 8. Information indicating whether or not there is a
 normal link among the 16 links, on the basis of the information stored in
 the buffer of FIG. 2, is stored in the `blink` field of the "reason"
 region. For example, if at least one link is normal, then normal state
 information is stored in the `blink` field. If there are no normal links,
 then abnormal state information is stored in the `blink` field.
 Information indicating whether or not it is possible to communicate
 through the 16 links of the trunk between BCP 10 and CCP 52 is stored in
 the `llink` field. Information representing whether or not there is a
 normal CIP out of the 3 CIPs assigned by one FA is stored in the fields
 `cip[0]` through `cip[n]`. The state information of the AGC is stored in
 the fields `agc[0][0]` through `agc[k][n]` according to each sector and
 each FA. State information of a low noise amplifier (LNA) is stored in the
 fields `lna[0][0]` through `lna[k][n]` according to each sector and each
 FA.
 The buffer at the right side of FIG. 5 has (i+1) transmitting mode regions
 designated "tx_mode[0]" through "tx_mode[i]". The parameter i is obtained
 by subtracting 1 from the maximum number of TIPs per BTS (i.e., 6).
 Therefore, there are 6 transmitting mode regions "tx_mode[0]" through
 "tx_mode[5]". Each transmitting mode region has transmitting information
 fields `snd_info[0]` through `snd_info[j]` in which transmitting power
 control information is stored. The transmitting power control information
 stored in the transmitting information fields `snd_info[0]` through
 `snd_info[j]` is based on the buffer of the left side. The parameter j is
 obtained by subtracting 1 from the maximum number of transceivers within a
 transceiver per BTS (i.e., 5, corresponding to XCVR(0) through XCVR(4)).
 Therefore, each of the transmitting mode regions "tx_mode[0]" through
 "tx_mod[5]" has 5 fields `snd_info[0]` through `snd_info[4]`.
 FIG. 6 illustrates a message structure for transmitting a transmitting
 power mode to a TIP. A destination address of the TIP is stored in a
 "destination address" region. A source address of the BCP is stored in a
 "source address" region. Information indicating whether a message is a
 control type or a traffic type message is stored in a "type" region. The
 message size is stored in a "length" region. An identification (ID) of a
 current signal is stored in a current signal ID region "sig_id". A sub ID
 of a source for discriminating processors within the source is stored in a
 source sub ID region "src_sub id". A sub ID of a destination for
 discriminting processors of the destination is stored in a destination sub
 ID region "des_sub_id" which has nothing to do with the transmitting power
 control of the present invention. The type of a plurality of message IDs
 of the current signal stored in the current signal ID region is stored in
 a message ID region "msg_ID". The state of a TIP and transceiver is stored
 in status regions "status[0][0]" through "status[5][4]". In a status
 region "status[x][y]", x indicates a TIP ID, and y indicates a transceiver
 ID (i.e., transceivers XCVR(0) through XCVR(4)) corresponding to the TIP.
 Thus, the designations x and y have values associated therewith from 0-5
 and 0-4, respectively. For example, in the status region "status[0][0]",
 the transmitting power control information at the first transceiver
 XCVR(0) within transceiver 24-0 corresponding to first TIP 22-0 is
 updated.
 FIG. 7 illustrates the relationship between the transmitting power control
 information, the sectors and the FAs. Referring to FIGS. 1 and 7, TIPs
 22-0, 22-1, and 22-2 (i.e., TIP 0, TIP 1 and TIP 2) correspond to sectors
 .alpha., .beta. and .gamma., respectively. The TIPs 22-3, 22-4 and 22-5
 (i.e., TIP 3, TIP 4 and TIP 5) also correspond to sectors .alpha., .beta.
 and .gamma., respectively. The same FA is assigned to transceivers of the
 same order within the transceivers 24-0, 24-1 and 24-2 or 24-3, 24-4 and
 24-5 corresponding to three TIPs 22-0, 22-1 and 22-2 (TIP 0, TIP 1 and TIP
 2) or 22-3, 22-4 and 22-5 (TIP 3, TIP 4 and TIP 5), respectively. For
 example, second transceivers XCVR(1) within transceivers 24-0, 24-1 and
 24-2 corresponding to TIPs 22-0, 22-1 and 22-2 (TIP 0, TIP 1 and TIP 2),
 respectively, use the same FA, namely first FA FA0. As another example,
 the last transceivers XCVR(4) within transceivers 24-3, 24-4 and 24-5
 corresponding to TIPs 22-3, 22-4 and 22-4 (TIP 3, TIP 4 and TIP 5),
 respectively, use the same FA, namely FA7. The transmitting power control
 information fields `snd_info[0]` through `snd_info[4]` correspond to
 transceivers XCVR(0) through 20 XCVR(4) within transceivers 24-0 through
 24-5. Since the transceivers XCVR(0) within transceivers 24-0 through 24-5
 are backup transceivers, an FA is not assigned to the transmitting power
 control information field `snd_info[0]` corresponding to the transceivers
 XCVR(0).
 An operation according to a preferred embodiment of the present invention
 will be described hereinbelow in detail with reference to FIGS. 1 to 7.
 However, before such a description is provided, some of the factors
 affecting the transmitting power of transceivers 24-0 through 24-5 are
 noted. Such factors include, for example, the state of the trunk (that is,
 the 16 links) between the BSC and the BTS, the state of the 24 CIPs, the
 state of the AGC, the state of the LNA alarm, etc. Judgements regarding
 whether or not to block the transmitting power, and the range of
 transceivers that will have their transmitting power blocked are described
 hereinbelow.
 First, the following information is applied to BSHX 12 of BCP 10:
 information which indicates the state of the trunk between BSC 50 and the
 BTS and which is reported from HIPA 18 to BSHX 12; information reported by
 communication with the BCP 10 from the CCP 52 within BSC 50 or by a self
 link test; or information which is not utilized by the user. The BSHX 12
 stores the received information in the `config_sts`, `test_sts` and
 `block_sts` fields of a corresponding link state information region
 "Link_State_Inform[x]" (where x is a value from 0-15) shown in FIG. 2.
 BSHX 12 then updates the state information of the links in the
 `state_flag` field of the corresponding link state information region
 "Link_State_Inform[x]" by the combination of the information stored in the
 `config_sts`, `test_sts` and `block_sts` fields. If information stored in
 any one of the `config_sts`, `test_sts` and `block_sts` fields is
 abnormal, then abnormal state information is updated in the `state_flag`
 field. If the information is all normal, then normal state information is
 updated in the `state_flag` field.
 Therefore, BSHX 12 can judge whether or not the state of a corresponding
 link has changed by the state flag information updated in the `state_flag`
 field.
 If the state of any link within the trunk is changed from a normal state to
 an abnormal state, BSHX 12 judges whether or not the state of the other
 links are all abnormal by sequentially checking the state flag information
 in the `state_flag` field of the link state information region
 "Link_State_inform[x]". If any one link is normal (i.e., at least one),
 then the call processing service can be normally performed, and the normal
 state information is stored in the `blink` field. If all the links of the
 trunk are abnormal, then the abnormal state information is stored in the
 `blink` field shown in FIG. 5. The BSHX 12 compares a current information
 value with a previous information value. If they are the same, there is no
 further processing. However, if they are different from each other, for
 example, if the value stored in the `blink` field is changed from the
 normal state to the abnormal state, BSHX 12 updates the abnormal state
 information in all the fields `snd_info[0]` through `snd_info[j]` of the
 transmission mode regions "tx_mode[0]" through "tx_mode[i]" shown in FIG.
 5.
 The BSHX 12 also copies the abnormal state information stored in fields
 `snd_info[0]` through `snd_info[j]` of each of the transmission mode
 regions "tx_mode[0]" "tx_mode[i]" to the status regions "status[0][0]"
 through "status[i][j]" of the message for transmitting a transmitting
 power mode to the TIPs (see FIG. 6). The copied message is transmitted to
 TIPs 22-0 through 22-5. If the trunk is abnormal, since the BTS cannot
 process a call, such a message for blocking the transmitting power of all
 the transceivers within the BTS is transmitted to TIPs 22-0 through 22-5.
 In FIG. 5, since the transmitting power control information stored in the
 field `snd_info[0]` indicates information corresponding to a backup
 transceiver, only the transmitting power control information stored in
 fields `snd_info[1]` through `snd_info[4]` (i.e., excluding field
 `snd_info[0]`) contain effective information. If the transmitting power
 control information stored in fields `snd_info[0]` through `snd_info[4]`
 indicate normal information, this represents that the transmitting power
 of the transceivers should be normally generated. If the information is
 abnormal, this represents that the transmitting power of the transceivers
 should be blocked.
 During the periodic transmitting and receiving of an answer-back message
 between BCP 10 and CCP 52, as well as externally reported information, if
 there is no answer for a predetermined period of time from the CCP 52
 (e.g., 12 seconds), BSHX 12 regards this state as an abnormal
 communication state. Hence, the abnormal state information is updated in
 the field `llink` illustrated in FIG. 5. Thereafter, the abnormal state
 information is stored in fields `snd_info[0]` through `snd_info[j]` of
 each of the transmission mode regions "tx_mode[0]" through "tx_mode[i]".
 The abnormal state information is copied to the status regions of the
 message of FIG. 6. The copied message is transmitted to TIPs 22-0 through
 22-5.
 If the communication is re-started, BSHX 12 updates the normal state
 information in the `llink` field shown in FIG. 5 and stores the normal
 state information in fields `snd_info[0]` through `snd_info[j]` of
 transmission mode regions "tx_mode[0]" through "tx_mode[i]". The normal
 state information is copied to the status regions of the message of FIG.
 6. The copied message is transmitted to TIPs 22-0 through 22-5.
 Second, BSHX 12 checks whether the 24 CIPs 28-0 through 28-n are in the
 keep-alive state through the periodic (for example, 3 seconds) answer-back
 message. If the state of any CIP has changed, BSHX 12 stores the abnormal
 or normal state information in the `ka_sts` field of the corresponding CIP
 state information region shown in FIG. 3. Meanwhile, BFMX 14 within BCP 10
 can indicate whether or not a fault is generated in the CIP. In this case,
 BSHX 12 stores "`ALM_ON(1)`" or "`ALM_OFF(0)`" in the `alarm_sts` field.
 The BSHX 12 determines the state of the `state_flag` field by combining
 the state of the `ka_sts` field with the state of the `alarm_sts` field.
 If the state of the `state_flag` field has changed, BSHX 12 confirms
 whether or not all the CIPs within the FA are normal by checking the state
 of the `state_flag` field. If all the CIPs within the FA are abnormal, the
 abnormal state information is stored in a corresponding one of the fields
 `cip[0]` through `cip[n]` shown in FIG. 5. The abnormal state information
 is also stored in a corresponding one of the fields `snd info[0]` through
 `snd_info[j]`. As illustrated in FIG. 7, 4 FAs per sector are assigned to
 each TIP. If the corresponding FAs are FA0, FA1, FA2 and FA3, BSHX 12
 sends a blocking message to TIPs 22-0, 22-1 and 22-2 (TIP 0, TIP 1 and TIP
 2). If the corresponding FAs are FA4, FA5, FA6 and FA7, BSHX 12 sends the
 blocking message to TIPs 22-3, 22-4 and 22-5 (TIP 3, TIP 4 and TIP 5).
 Third, the state of the AGC is reported from CIPs 28-1 through 28-n. Each
 CIP has a path according to sectors .alpha., .beta. and .gamma..
 Therefore, BSHX 12 stores the state of the AGC in each bit shown in FIG. 4
 according to the ID of the CIP. If the state of the AGC is changed from
 the normal state to the abnormal state, BSHX 12 updates the abnormal state
 information in the corresponding field `agc[sector][fa]` illustrated in
 FIG. 5. The abnormal state information is also updated in the
 corresponding field among fields `snd_info[0]` through `snd_info[j]`.
 Thereafter, BSHX 12 sends the blocking message only to the TIP in which
 the transceiver assigned to a corresponding subcell is contained.
 Fourth, since the LAN receives information regarding an alarm state, a
 corresponding sector and a respective FA from BFMX 14, BSHX 12 updates the
 normal or abnormal state information in the corresponding field
 `lna[sector][fa]` and in the corresponding field among fields
 `snd_info[0]` through `snd_info[j]` indicated in FIG. 5. Thereafter, BSHX
 12 sends the blocking message only to the TIP in which the transceiver
 assigned to a corresponding subcell is contained.
 A method for updating the information in fields `snd_info[0]` through
 `snd_info[j]` illustrated in FIG. 5 is described hereinafter. If any
 factor among the above-described factors affecting the transmitting power
 of transceivers 24-0 through 24-5 is generated, and results in information
 stored in a corresponding field of the reason region, BSHX 12 checks the
 field `blink` or `llink`. If one of the two fields is abnormal, the
 transmitting power control information stored in fields `snd_info[0]`
 through `snd_info[j]` are all abnormal since it is impossible to provide
 the call processing service. If the trunk is normal, that is, if normal
 state information is stored in `blink` and `llink` fields, BSHX 12 checks
 fields `cip[0]` through `cip[n]`. If the abnormal state information is
 stored in any one of fields `cip[0]` through `cip[n]`, then the abnormal
 state information is updated in the field corresponding to the respective
 FA of all the sectors among fields `snd_info[0]` through `snd_info[j]`.
 The normal or abnormal state information is updated in the corresponding
 field among fields `snd_info[0]` through `snd_info[j]` according to the
 respective sector and FA.
 As noted above, if a factor (corresponding to a fault) is generated from
 the devices which may affect call service, the range of influence of the
 corresponding device (i.e., the range of influence of the fault) is
 determined and a message for blocking transmitting power is sent to the
 respective TIP(s). If normal service is possible, a message for normally
 transmitting the transmitting power is sent to the respective TIP(s).
 Through such processes, abnormal circumstances affecting the determined
 range will not effect existing service. Further, even if a specific BTS
 does not provide the call processing service due to a fault, an adjacent
 BTS can process the call.
 That is, if the BTS cannot perform the call processing service normally,
 the transmitting power of the BTS is blocked. If the factor affecting the
 call processing service has ceased, then the transmitting power of the BTS
 is restored. Therefore, there is no interference with other normal systems
 and call service quality is improved.
 While the invention has been shown and described with reference to certain
 illustrative embodiments thereof, it will be understood by those skilled
 in the art that various changes in form and details may be made therein
 without departing from the spirit and scope of the invention as defined by
 the appended claims.