Antenna Hopping

During a call connection, a burst can easily be lost when the mobile station happens to be located in a fading dip for that particular frequency, or if it is subjected to interference. The coding and interleaving scheme in GSM is constructed so that loss of a single burst has minimal influence on the speech quality. The probability that several bursts within a speech frame have poor signal quality is reduced if the bursts are transmitted on different paths. This can be done by using antenna hopping. With antenna hopping, transmit diversity is introduced by changing transmit antenna between bursts.


                                                  Schematic picture of antenna hopping

This transmit diversity scheme mimics frequency hopping in the sense that the fading changes rapidly between bursts due to transmission through different paths.
From a subscriber point of view, antenna hopping gives an improved speech quality.
From an operator point of view, antenna hopping is a very attractive scheme in particular for traffic channels without frequency hopping, but also for traffic channels frequency hopping over a relatively low number of frequencies, where it can provide substantial diversity gains. What makes antenna hopping especially interesting as a transmit diversity scheme is the fact that it can be used without increasing the number of TRXs in a base station. Thus giving the operator the following benefits:

  • a possibility to tighter frequency reuse and increase in capacity,
  • a more robust radio environment,
  • a possibility to give subscribers a more uniform speech quality. 

Antenna hopping can reduce the effect of multipath fading. With antenna hopping, a non-moving mobile will typically not remain in a specific fading dip longer than one TDMA frame. The low signal strength dips in multipath fading are thus leveled out, and the mobile will perceive a more constant radio environment.


Schematic picture of multipath fading at one frequency and antenna hopping between two antennas for a slow/non-moving mobile station 

Antenna Hopping Parameters 
AHOP
: Defines the wanted state for antenna hopping on a transceiver group. The wanted state can be either of ON, ONXC0 or OFF. In state ONXC0, all channels except those on the BCCH frequency/frequencies will antenna hop.



Measurement Result Recording (MRR)

Measurement Result Recording (MRR) is a tool for measuring the radio characteristics of the connections between MSs and the network. MRR records information on the radio characteristics of the dedicated channels and calculates statistics on the data recorded.
MRR utilises the data that the BSC receives from the BTS in Measurement Results. These data include the results of the measurements performed by both the BTS and the MS.
The purpose of the feature is to provide the operator with a facility for compiling statistics on the radio interface. The feature makes it easier for the operator to supervise the radio network. It also makes it possible for the operator to determine correlations within the collected data.
The MRR application can be used for:
  • Supervision of the network performance
  • Troubleshooting of the network
  • Comparison of the network performance before and after a change is made to the network
MRR is a feature in the Operation and Support System (OSS). Recordings can be defined, scheduled, ended, stored and processed in OSS. The user can generate a large number of reports that can be used to analyse each recording and make comparisons. MRR is based on a function in the BSC, where it is possible to initiate and to end a recording by command. All data are recorded initially by the BSC and stored in a binary file that can be output directly or forwarded to OSS for further processing.
The measured radio characteristics are:
  • Signal strength in both Uplink (UL) and Downlink (DL).
  • Signal Quality in both UL and DL.
  • Timing Advance (TA).
  • Power level used by the MS and Power reduction of the BTS.
  • UL and DL Pathloss.
  • Pathloss difference (Pathloss DL - Pathloss UL).
The radio characteristics can be recorded for one or more cell sets simultaneously by initiating one or more recordings. A cell set can comprise one or more cells.
The user can filter the data received from a Measurement Result by specifying recording thresholds. Recording thresholds can be specified for either one or two specified radio characteristics. The use of recording thresholds allows the user to determine: radio performance, the causes of poor radio performance and correlations between different radio characteristics. As a special filtering option, connections using Adaptive Multi Rate full rate (AMR FR) can be selected to be included or excluded from the results.


LTE relation with CDMA2000 Parameter


Parameter Name
Parameter Description
Default Value
Cdma2000CellRelationId
The value component of the Relative Distinguished Name (RDN).

externalCdma2000CellRef
Reference to a ExternalCdma2000Cell.

includeInSystemInformation
Indicates if the CDMA2000 cell referred to is included in System Information.
When the includeInSystemInformation is set to false, the CDMA2000 cell is not  included in SIB8.
A maximum of 32 CDMA2000 cells can be included in SIB8.
true
freqCdma
Identifies the carrier frequency within a CDMA2000 Band.

Cdma2000FreqId
The value component of the Relative Distinguished Name (RDN).

reservedBy
Contains a list of MO instances that reserve this MO instance.

Cdma2000FreqBandId
The value component of the Relative Distinguished Name (RDN).

hrpdBandClass
The CDMA-HRPD frequency band in which the HRPD carrier is located.

reservedBy
Contains a list of MO instances that reserve this MO instance.

Cdma2000FreqBandRelationId
The value component of the Relative Distinguished Name (RDN).

cdma2000FreqBandRef
Reference to the Cdma2000 frequency band MO, Cdma2000FreqBand.

threshXHighHrpd
The threshold used in reselection towards a high priority CDMA2000 HRPD band class, expressed as an unsigned binary number equal to FLOOR ([-2 x 10 x log10 Ec/Io]) in units of 0.5 db.

If sNonServingCell > threshXHighHrpd, reselection is considered towards the band class with higher priority. The condition must be valid during the period defined by attribute tReselectionCdmaHrpd.

sNonServingCell is the RX-level value of a neighboring cell.
63
threshXLowHrpd
The threshold used in reselection towards a low priority CDMA2000 HRPD band class expressed as an unsigned binary number equal to FLOOR ([-2 x 10 x log10 Ec/Io]) in units of 0.5 db.
If sServingCell < threshServingLow and sNeighbor > threshXLow (see corresponding attribute), reselection towards this lower prioritized band class is considered. The condition must be valid during the period defined by attribute tReselectionCdmaHrpd.

sServingCell is the RX level value of the serving cell and sNeighborCell is the RX level value of a neighbor frequency.
63
cellReselectionPriority
Absolute priority of the RAT (0 means: lowest priority).
6
Cdma2000FreqRelationId
The value component of the Relative Distinguished Name (RDN).

connectedModeMobilityPrio
Prioritizes CDMA2000 frequencies among all frequencies related to the cell for UEs in connected mode.
(0 means the lowest priority)
6
qOffsetFreq
Indicates a frequency-specific offset to apply when evaluating triggering conditions for measurement reporting.
0
cdma2000FreqRef
Reference to the Cdma2000Freq MO

Cdma2000NetworkId
The value component of the Relative Distinguished Name (RDN).

LTE ANR Parameter


Parameter Name
Parameter Description
Default Value
AnrFunctionId
The value component of the Relative Distinguished Name (RDN).

cellAddRankLimitEutran
Threshold value for reported rank for a cell to be automatically added as neighbor.
1
cellAddRsrpOffsetEutran
Threshold offset value for reported power for a cell to be automatically added as neighbor.
-10
cellAddRsrpThresholdEutran
Threshold value for reported power for a cell to be automatically added as neighbor.
-1440
cellAddRsrqOffsetEutran
Threshold offset value for reported quality for a cell to be automatically added as neighbor.
-10
cellAddRsrqThresholdEutran
Threshold value for reported quality for a cell to be automatically added as neighbor.
-1920
hoAllowedEutranPolicy
Starting value of the attribute isHoAllowed when a EUtranCellRelation is created by Automated Neighbor Relations (ANR).
true
removeNcellTime
The length of time that neighbor cells without any neighbor relations remain in the RBS. 1000 means no automatic removal is performed. If set to 0, the neighbor cell MO is removed within 1 minute.
30
removeNenbTime
The length of time that neighbor RBSs without any neighbor cells remain in the RBS. 1000 means no automatic removal is performed. If set to 0, the neighbor RBS MO is removed within 1 minute.
7
removeNrelTime
The length of time that neighbor relations without any communication to the neighbor cell remain in the RBS. 1000 means no automatic removal is performed. If set to 0, the neighbor relation MO is removed within 1 minute.
30
x2SetupPolicy
Indicates if X2 is set up when an ExternalEnbFunction not in the x2BlackList is created by Automated Neighbor Relations (ANR).
true
anrUesEUtraIntraFMax
The maximum target number of UEs in each cell that are assigned Automated Neighbor Relations (ANR)-specific thresholds for E-UTRAN intra-frequency neighbor cell reports. The actual number of UEs with these thresholds may deviate from the target.
20
anrUesEUtraIntraFMin
The minimum target number of UEs in each cell that are assigned Automated Neighbor Relations (ANR)-specific thresholds for E-UTRAN intra-frequency neighbor cell reports. The actual number of UEs with these thresholds may deviate from the target.
1
anrUesEUtraIntraFDecr
The decrease in the target number of UEs in each cell that are assigned Automated Neighbor Relations (ANR)-specific thresholds for E-UTRAN intra-frequency neighbor cell reports, every time a neighbor cell report is received with only known neighbor cells.
10
anrUesEUtraIntraFIncrHo
The increase in the target number of UEs in each cell that are assigned Automated Neighbor Relations (ANR)-specific thresholds for E-UTRAN intra-frequency neighbor cell reports, every time a neighbor cell report for handover is received with unknown neighbor cells.
100
anrUesEUtraIntraFIncrAnr
The increase in the target number of UEs in each cell that are assigned Automated Neighbor Relations (ANR)-specific thresholds for E-UTRAN intra-frequency neighbor cell reports, every time a neighbor cell report for ANR is received with unknown neighbor cells.
20

LTE Paging Parameter

Parameter Name
Parameter Description
Default Value
PagingId
The value component of the RDN.

maxNoOfPagingRecords
The maximum allowed number of paging records included in one Radio Resource Control (RRC) paging message. It is the allowed maximum number of UE that can be paged per paging occasion.
3
defaultPagingCycle
The paging cycle (also referred to as T) used by the RBS and broadcast in system information type 2. If the UE-specific Discontinuous Reception (DRX) cycle is provided in S1AP paging and has a smaller value than defaultPagingCycle, the UE-specific DRX cycle overrides defaultPagingCycle.
128
nB
Used to calculate the number and position of Paging Occasions (PO) and Paging Frames (PF).
The numerical value of nB depends on the value of the defaultPagingCycle (T) and can be set to one of the following values:
4T, 2T, T, 1/2T,1/4T, 1/8T, 1/16T, 1/32T
When nB is set to T, 2T or 4T, it determines the number of POs per PF, and the PO position in PF.
When nB is set to a value smaller than T, it affects the System Frame Number of the PF, the position of PO in the PF, and also distribution of UE into groups with the same PF.
When nB is set to a  smaller value, the groups are fewer but larger, or more but smaller.
T
pagingDiscardTimer
The length of time a received paging is retained or queued in the RBS before it is discarded. The timer should be set to the same (or smaller) value as the paging resend timer in MME (T3413). This setting  prevents the RBS from retaining or sending an old paging after the re-sent copy is received from the MME.
3

LTE Admission Control Parameter

Parameter Name
Parameter Description
Default Value
paArpOverride
Allocation Retention Priority level received from the Core Network that eNB interprets as the identifier for Privileged Access.
The value zero will disable Privileged Access ARP override.
7
ulNonGbrRatio
This parameter sets the wanted uplink resource utilization ratio of Non-GBR bearers, e.g. for Mobile Broadband users, on transport network. The value given in this parameter specifies the Non-GBR part of the total bandwidth and the remaining part (1-ulNonGbrRatio) sets the GBR part of the total bandwidth. The parameter will be used by the Admission Control to balance GBR and Non-GBR use of resources.
500
dlNonGbrRatio
This parameter sets the wanted downlink resource utilization ratio of Non-GBR bearers, e.g. for Mobile Broadband users, on transport network. The value given in this parameter specifies the Non-GBR part of the total bandwidth and the remaining part (1-dlNonGbrRatio) sets the GBR part of the total bandwidth. The parameter will be used by the Admission Control to balance GBR and Non-GBR use of resources.
500
AdmissionControlId
The value component of the Relative Distinguished Name (RDN).

emergencyArpLimit
ARP (Allocation Retention Priority) value limit used for identifying ARP values that are considered to be part of the emergency (high priority) group. This limit value and all values below are considered to be of high priority. The value zero is introduced to turn off ARP handling.
7
nrOfBearersReserved
Number of bearers reserved for high priority group (bearers with low ARP values, Allocation Retention Priority values). Setting a high value for the reservation means low priority bearers will always be rejected.
0
nrOfRrcConnectedReserved
Number of RRC connections reserved for high priority UEs (handovers and where establishment cause is emergency). Setting a high value means non emergency UEs will always be rejected.
0
dlGbrAdmThresh
Admission threshold for load due to Guaranteed Bit Rate (GBR) bearers in the downlink, expressed as a fraction of the available resources.
1000
dlTransNwBandwidth
Downlink transport network bandwidth for LTE.
1000
ulGbrAdmThresh
Admission threshold for load due to Guaranteed Bit Rate (GBR) bearers in the uplink, expressed as a fraction of the available resources.
1000
ulTransNwBandwidth
Uplink transport network bandwidth for LTE.
1000