Set Idle Basic Parameters of Cell(SET GCELLIDLEBASIC) Function Use this command to set basic call idle parameters of a cell.
Note 1. When the cell broadcast service is supported and the CBCH is CBCH+SDCCH8, the value of "Num of CCCH blocks Rsved for AGCH" cannot be smaller than 1. 2. When the CCCH is configured as a combined CCCH, the value of "Num of CCCH blocks Rsved for AGCH" ranges from 0 to 2. Otherwise, it ranges from 0 to 7.
Parameters Parameter ID
IDTYPE
Parameter Name
Index Type
Parameter Description Meaning: Type of an index. GUI Value Range: BYNAME(By Name), BYID(By Index) Unit: None Actual Value Range: BYNAME, BYID MML Default Value: None Recommended Value: None Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: None
CELLID
Cell Index
Meaning: Index of a cell, uniquely identifying a cell in a BSC. GSM cells are uniquely but not necessarily consecutively numbered within a BSC. For example, you can number a GSM cell 0 and number another GSM cell 3. GUI Value Range: 0~2047 Unit: None Actual Value Range: 0~2047 MML Default Value: None Recommended Value: None
Parameter ID
Parameter Name
Parameter Description
Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: None CELLNAME
Cell Name
Meaning: Name of a cell. This parameter uniquely identifies a cell in a BSC. Cell names cannot contain the following invalid characters: ,;="' In addition, cell names cannot contain two or more consecutive %, two or more consecutive spaces, or more than three consecutive +. GUI Value Range: None Unit: None Actual Value Range: 1~64 characters MML Default Value: None Recommended Value: None Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: None
ATT
Attach-detach Allowed
Meaning: Attach-detach Allowed (ATT). If this parameter is set to YES, when an MS is powered off, the network does not process any call connection for the MS as a called party. In this way, the network processing time and resources are saved. GUI Value Range: NO(No), YES(Yes) Unit: None Actual Value Range: NO, YES MML Default Value: None Recommended Value: YES(Yes)
Parameter ID
Parameter Name
Parameter Description
Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: None TX
TX-integer
Meaning: Tx-integer (T for short). This parameter specifies the number of timeslots between two transmissions when an MS sends multiple consecutive channel requests. The access algorithm is defined in 3GPP TS 04.08 to reduce the collisions on the RACH and improve the efficiency of the RACH. The algorithm specifies three parameters: Tx-integer (T for short), maximum number of retransmissions (RET), and S related to channel combination. This parameter works with the configuration of the CCCH to determine the parameter S. The relationships between this parameter and the configuration of the CCCH are as follows: When this parameter is set to 3, 8, 14, or 50, S is 55 if the CCCH and SDCCH do not share a physical channel. When this parameter is set to 3, 8, 14, or 50, S is 41 if the CCCH and SDCCH share a physical channel. When this parameter is set to 4, 9, or 6, S is 76 if the CCCH and SDCCH do not share a physical channel. When this parameter is set to 4, 9, or 6, S is 52 if the CCCH and SDCCH share a physical channel. When this parameter is set to 5, 10, or 20, S is 109 if the CCCH and SDCCH do not share a physical channel. When this parameter is set to 5, 10, or 20, S is 58 if the CCCH and SDCCH share a physical channel. When this parameter is set to 6, 11, or 25, S is 163 if the CCCH and SDCCH do not share a physical channel. When this parameter is set to 6, 11, or 25, S is 86 if the CCCH and SDCCH share a physical channel. When this parameter is set to 7, 12, or 32, S is 217 if the CCCH and SDCCH do not share a physical channel. When this parameter is set to 7, 12, or 32, S is 115 if the CCCH and SDCCH share a physical channel. The timeslot for sending messages is a random value from the collection of {0, 1..., MAX(T, 8)-1}. The number of timeslots (excluding the timeslot used to send messages) between two adjacent channel request messages is a random value from the collection of {S, S+1, ..., S+T-1}. When T increases, the interval between two adjacent channel requests increases, and RACH conflicts decrease. When S increases, the interval between two adjacent channel request messages increases, and RACH conflicts
Parameter ID
Parameter Name
Parameter Description decrease, thus improving the usage of AGCH and SDCCH. The access time of the MS, however, is prolonged and the network performance is decreased when T and S increase. Under normal conditions, an appropriate T value should be used to ensure that S is as low as possible, and ensure that AGCH and SDCCH are not overloaded. GUI Value Range: TX_3(3), TX_4(4), TX_5(5), TX_6(6), TX_7(7), TX_8(8), TX_9(9), TX_10(10), TX_11(11), TX_12(12), TX_14(14), TX_16(16), TX_20(20), TX_25(25), TX_32(32), TX_50(50) Unit: None Actual Value Range: TX_3, TX_4, TX_5, TX_6, TX_7, TX_8, TX_9, TX_10, TX_11, TX_12, TX_14, TX_16, TX_20, TX_25, TX_32, TX_50 MML Default Value: None Recommended Value: TX_32(32) Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: If the number of RACH conflicts in a cell is large, T should be set to a large value. If the number of RACH conflicts in a cell is small, T should be set to a small value. The increase in T and S prolongs the access time of an MS, deteriorating the access performance of the entire network. Therefore, appropriate values should be selected for T and S. When the network traffic is heavy, the success rate of immediate assignment is low if the sum of S and T is small. Therefore, the value of T should be properly adjusted to ensure that the sum of S and T is great. The default value 32 is used when the Abis interface uses satellite transmission.
CBA
Cell Bar Access
Meaning: Used together with Cell Bar Qualify to decide the priority status of a cell. Refer to GSM Rec. 04.08. Cell Bar Qualify Cell Bar Access Cell selection priority Cell reselection priority NO NO Normal Normal NO YES Prohibited Prohibited YES NO Low Normal YES YES Low Normal GUI Value Range: NO(NO), YES(YES)
Parameter ID
Parameter Name
Parameter Description
Unit: None Actual Value Range: NO, YES MML Default Value: None Recommended Value: The CBA function applies to special scenarios. If this parameter is set to YES and Cell Bar Qualify is set to no, only handovers are allowed in a cell, and direct access of an MS is not allowed. This condition applies to a dual-network coverage cell. For a common cell, this parameter should be set to NO. Parameter Relationship: The cell priority is determined by both CBQ and this parameter. Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: None CBQ
Cell Bar Qualify
Meaning: Used together with Cell Bar Access to decide the priority status of a cell. See GSM Rec. 0408. This parameter does not affect cell reselection but cell selection only. Cell Bar Qualify Cell Bar Access Cell selection priority Cell reselection priority NO NO Normal Normal NO YES Prohibited Prohibited YES NO Low Normal YES YES Low Normal GUI Value Range: NO(No), YES(Yes) Unit: None Actual Value Range: NO, YES MML Default Value: None Recommended Value: NO(No) Parameter Relationship: The cell priority is determined by both CBA and this parameter. Service Interrupted After Modification: No (And no impact on the UE in idle mode)
Parameter ID
Parameter Name
Parameter Description Impact on Network Performance: None
BSAGBLKSRES
CCCH Blocks Reserved for AGCH
Meaning: BS-AG-BLKS-RES, indicating the number of the CCCH message blocks reserved for the AGCH. After the CCCHs are configured, the value of this parameter indicates the actual seizure rates of the AGCHs and the PCHs over the CCCHs. GUI Value Range: 0~7 Unit: None Actual Value Range: 0~7 MML Default Value: None Recommended Value: 1 Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: The setting of this parameter affects the MS paging response and performance of the system. A large value decreases the number of paging blocks, paging capacity, and paging success rate.
BSPAMFRAMS
Multi-Frames in a Cycle on the Paging CH
Meaning: Number of multiframes in a cycle on a paging sub-channel. In fact, this parameter specifies the number of paging sub-channels that a paging channel in a cell is divided into. In an actual network, an MS does not listen to other paging sub-channels but its belonging paging sub-channel only. For details, see 3GPP TS 05.02 and 05.08. The larger the value of this parameter, the more the number of the paging sub-channels in a cell, and the fewer the number of the users belonging to each paging sub-channel. In this case, the mean uptime of the MS battery can be prolonged. For details, see the computing mode of paging group in 3GPP TS 05.02. The larger the value of this parameter, however, the larger the time delay of a paging message in a space segment. Therefore, the average service performance of the system lowers. Based on the principle of ensuring that overload does not occur on paging channels, set this parameter to a value as small as possible. You must regularly measure the overload conditions of the paging channels in a running network and accordingly adjust the value of this parameter properly. A paging message in a location area must be sent in all the cells within this
Parameter ID
Parameter Name
Parameter Description location area at the same time. Therefore, the capacity of a paging channel of each cell in a location area must be the same or nearly the same. The capacity refers to the calculated number of paging sub-channels of each cell. GUI Value Range: 2_M_PERIOD(2 Multiframe Period), 3_M_PERIOD(3 Multiframe Period), 4_M_PERIOD(4 Multiframe Period), 5_M_PERIOD(5 Multiframe Period), 6_M_PERIOD(6 Multiframe Period), 7_M_PERIOD(7 Multiframe Period), 8_M_PERIOD(8 Multiframe Period), 9_M_PERIOD(9 Multiframe Period) Unit: 470ms Actual Value Range: 940~4230 MML Default Value: None Recommended Value: 2_M_PERIOD(2 Multiframe Period) Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: If this parameter is set to a large value, the number of paging subchannels in a cell increases and the number of MSs on each paging subchannel decreases. This can prolong the average service life of MS batteries but increase the delay in sending paging messages. Therefore, the system performance deteriorates. If this parameter is set to a small value, the number of paging subchannels in a cell decreases and the number of MSs on each paging subchannel increases. This is likely to cause the overload on paging subchannels.
T3212
T3212
Meaning: This parameter specifies the length of the timer for periodic location update. GUI Value Range: 0~255 Unit: 6min Actual Value Range: 0~1530 MML Default Value: None Recommended Value: 20
Parameter ID
Parameter Name
Parameter Description Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: If this parameter is set to a smaller value, the paging success rate increases but the load on the SDCCH also increases, thus causing congestion on the SDCCH.
CRH
Cell Reselect Hysteresis Parameters
Meaning: Cell reselection hysteresis. This is one of the parameters used to decide whether to reselect cells in different location areas. Setting this parameter can avoid an increase in network signaling traffic due to frequent location updates and reduce the risk of losing paging messages. For details, see 3GPP TS 05.08 and 3GPP TS 04.08. GUI Value Range: 0dB, 2dB, 4dB, 6dB, 8dB, 10dB, 12dB, 14dB Unit: dB Actual Value Range: 0dB, 2dB, 4dB, 6dB, 8dB, 10dB, 12dB, 14dB MML Default Value: None Recommended Value: 6dB Parameter Relationship: None Service Interrupted After Modification: No (Impact on the UE in idle mode) Impact on Network Performance: The MS cannot respond to the paging during the location update, decreasing the call completion rate in the system. If this parameter is set to a small value, ping-pong location updates occur, increasing the signaling load on the SDCCH. If this parameter is set to a large value, the MS cannot camp on an optimum cell for a long time after entering a new location area.
PI
Cell Reselect Parameters Indication
Meaning: Cell Reselect Parameters Indication (PI), sent on the broadcast channel, indicates whether Cell Reselect Offset, Cell Reselect Temporary Offset in the SET GCELLIDLEAD command, and Cell Reselect Penalty Time are used. GUI Value Range: NO(No), YES(Yes)
Parameter ID
Parameter Name
Parameter Description
Unit: None Actual Value Range: NO, YES MML Default Value: None Recommended Value: YES(Yes) Parameter Relationship: None Service Interrupted After Modification: No (Impact on the UE in idle mode) Impact on Network Performance: The MS calculates C1 and C2 of the serving cell at a minimum interval of 5s. When necessary, the MS re-calculates C1 and C2 of all non-serving cells (neighboring cells). The MS constantly checks whether a cell reselection is required by checking following conditions: Whether the path loss (C1) of the current serving cell drops below 0 within 5s. If yes, the path loss is too large. C2 of an appropriate non-serving cell exceeds that of the serving cell in 5s and the following conditions are met: The C2 of a new cell in another LAC minus CRH (broadcast in the system information 3 and 4 of the serving cell) exceeds C2 of the serving cell in 5s. A cell reselection is performed in the last 15s, and the C2 of the new cell minus 5 dB constantly exceeds the C2 of the serving cell in 5s. A better cell exists if the above conditions are met. If a better cell exists, the MS reselects a cell, and does not select the previous cell within 5s. NCCPERMIT
NCC Permitted
Meaning: A set of NCCs of the cells to be measured by the MS. This parameter is an information element (IE) in the system information type 2 and 6 messages. If a bit of the value of this parameter is set to 1, the MS reports the corresponding measurement report to the BTS. The value of this parameter has a byte (eight bits). Each bit maps with an NCC (0~7) and the most significant bit corresponds to NCC 7. If bit N is 0, the MS does not measure the cell level of NCC N. GUI Value Range: SELECTION0_PERM(Selection of 0 Perm.), SELECTION1_PERM(Selection of 1 Perm.), SELECTION2_PERM(Selection of 2 Perm.), SELECTION3_PERM(Selection of 3 Perm.), SELECTION4_PERM(Selection of 4 Perm.), SELECTION5_PERM(Selection of 5 Perm.), SELECTION6_PERM(Selection of 6 Perm.), SELECTION7_PERM(Selection of 7 Perm.)
Parameter ID
Parameter Name
Parameter Description Unit: None Actual Value Range: SELECTION0_PERM, SELECTION1_PERM, SELECTION2_PERM, SELECTION3_PERM, SELECTION4_PERM, SELECTION5_PERM, SELECTION6_PERM, SELECTION7_PERM MML Default Value: None Recommended Value: SELECTION0_PERM1&SELECTION1_PERM-1&SELECTION2_PERM1&SELECTION3_PERM-1&SELECTION4_PERM1&SELECTION5_PERM-1&SELECTION6_PERM1&SELECTION7_PERM-1 Parameter Relationship: None Service Interrupted After Modification: No (And no impact on the UE in idle mode) Impact on Network Performance: The most significant three bits of BSIC for all cells map with the NCC. NCC Permitted should be set properly to avoid too many call drops. The MS does not report the information on the neighboring cells in the network whose corresponding NCC bit is set to 0. Therefore, this parameter should be set properly. Otherwise, an MS during an ongoing call cannot perform normal handover and a cross-coverage call drop occurs. For details, see 3GPP TS 05. 08. During an ongoing call, the MS reports to the BTS the signal information on neighboring cells. A report covers a maximum of six cells. Therefore, the MS should report those possible target cells, rather than selecting cells only based on the signal level. Generally, the MS does not report the information on the cells belonging to other GSM PLMNs. This function enables the MS to measure only those specified cells. This parameter specifies the codes of the NCCs to be measured by the MS. On the SCH, the system constantly transmits the BSIC, the first three bits of which indicate the NCC. Therefore, the MS needs to compare only this parameter with the adjacent NCCs measured. Then, the MS reports the matched NCCs to the BTS and discards others. The setting of this parameter affects only those MSs during conversation, as well as boundary handovers.
CRO
Cell Reselect Offset
Meaning: Cell Reselect Offset (CRO), indicating a correction of the C2. Proper setting of this parameter can reduce the number of handover times, helpful for assigning an MS to a better cell. In a special case that the PT is 31, the larger the CRO value is, the lower the possibility of handing over an MS to the cell.
Parameter ID
Parameter Name
Parameter Description Generally, do not set the CRO to a value larger than 25 dB. The CRO with a too large value will cause uncertain states in a network. The CRO values of the cells with different priorities in a network are almost the same. For details, see 3GPP TS 05.08 and 04.08. The setting of this parameter affects only the MSs supporting the protocol of GSM Phase 2 or a later version. GUI Value Range: 0~63 Unit: 2dB Actual Value Range: 0~126 MML Default Value: None Recommended Value: 0 Parameter Relationship: This parameter is valid only when PI is set to YES. Service Interrupted After Modification: No (Impact on the UE in idle mode) Impact on Network Performance: Setting this parameter to an appropriate value can decrease the number of handovers and help assign an MS to a better cell. If PT is set to 31, the larger the value of CRO, the lower the possibility of handing over an MS to the cell. Generally, CRO is set to a value smaller than or equal to 25 dB. If CRO is set to a too large value, the network will experience unexpected problems.
Example To set basic call idle parameters of a cell (Cell Index = 0; Attachdetach allowed = No; Tx-integer = TX_5; Cell Bar Access = No), run the following command: SET GCELLIDLEBASIC: IDTYPE=BYID, CELLID=0, ATT=NO, TX=TX_5, CBA=NO;
