Lte capacity monitoring

HUAWEI TECHNOLOGIES CO., LTD.
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LTE Capacity Monitoring

Monitoring
Principle
Measurement Formula
Monitoring
Threshold
Impact Proposed solution
Resource block
utilization DL RB Utilization
L.ChMeas.PRB.DL.Used.Avg/L.ChM
eas.PRB.DL.Availx100%
DL RB Utilization
>70% &
DL User Throughput
< 2Mbps
User may failed in
admission or poor user
experience
1. Add eNodeB
2. Bandwidth expansion
DL User throughput L.Thrp.bits.DL/L.Thrp.Time.DL/1000
UL RB Utilization
L.ChMeas.PRB.UL.Used.Avg/L.ChM
eas.PRB.UL.Availx100%
UL RB Utilization
>70% &
UL User Throughput
< 512kbps
User may failed in
experience
1. Add eNodeB
2. Bandwidth expansion
UL User throughput L.Thrp.bits.UL/L.Thrp.Time.UL/1000
RRC connected
users per cell (BBU
board specification)
Synchronized User
Utilization
L.Traffic.User.Avg/1200*100%
(Max num user handled in a cell for
LBBPd is 1200)
60% Poor user experience
1. Reduce UE inactivity timer in eNodeB (MOD
RRCCONNSTATETIMER). Please note that load in CPU will
increase if timer value reduce.
2. Physical tuning by balancing the target serving area for all
cells
3. Add cell
Preamble usage
for random access
Random Preamble
Utilization
(L.RA.GrpA.Att+L.RA.GrpB.Att)
/3600/N* 100%
(N is a value from product design in
considering probability of preamble
conflict, N is 50.)
75% Access delayed or failure
1. Enable resource adjustment algo
(MOD CELLALGOSWITCH: LocalCellId=xx,
RachAlgoSwitch=RachAdjSwitch-1;)
2. Enable adaptive backoff function to allow UE retransmit
preamble after failure
(MOD CELLALGOSWITCH: LocalCellID=xx,
RachAlgoSwitch=BackOffSwitch-1;)
Dedicated Preamble
Utilization
L.RA.Dedicate.Att/3600/100*100% 75% Access delayed or failure
1. Enable resource adjustment algo & reuse dedicated
preamble
(MOD CELLALGOSWITCH: LocalCellId=xx,
RachAlgoSwitch=RachAdjSwitch-1,
RachAlgoSwitch=MakeIdxSwitch;)
Control channel
element for
PDCCH
CCE Utilization
(L.ChMeas.CCE.CommUsed +
L.ChMeas.CCE.ULUsed +
L.ChMeas.CCE.DLUsed)/L.ChMeas.
CCE.Avail
70%
Scheduling delayed or
poor user experience
1. Add cell
LTE Capacity Monitoring Summary

LTE Capacity Monitoring Summary
Monitoring
Principle
Measurement Formula
Monitoring
Threshold
Impact Proposed solution
Maximum allowed
connected users
per eNodeB
RRC Connected User
Utilization
Sum (L.Traffic.User.Avg of all
cells)/Licensed RRC connected
users*100%
60%
User may failed in
experience
1. Increase license RRC (if CPU board usage <60%)
2. Add eNB (if CPU board usage >60%)
Traffic volume
utilization per
eNodeB
Traffic Volume Utilization
Sum of (L.Thrp.bits.UL +
L.Thrp.bits.DL) all cells / (Traffic
License*3600)
/(1000*1000)*100%
1. Increase Traffic volume license
Paging message
processing
capability (eNodeB
specification)
Paging Utilization
Sum of (L.Paging.S1.Rx) all cells
/3600/750 *100%
1. Reduce num cells in tracking area list
2. Paging policy (core network) optimization
Main control board
processing
capability
Main Control Board Usage VS.BBUBoard.CPULoad.Mean 60%
Poor user experience
1. Physical tuning to achieve load balancing between
neighbour (if neighbour is lightly loaded)
2. Change UMPT board (if LMPT is used)
3. Add eNB% of Main Control Board
Usage exceeed threshold
VS.Board.CPULoad.Cumulative
HighloadCount/(3600/5)*100%
5%
Baseband board
processing
capability
Main Control Board Usage VS.BBUBoard.CPULoad.Mean 60%
1. Add LBBP to share load
2. Move cells or add cells based on num of UEs
3. If already reached 6 LBBPs, add eNB% of Main Control Board
Usage exceeed threshold
VS.Board.CPULoad.Cumulative
HighloadCount/(3600/5)*100%
5%
Transmission rate
at Ethernet port
DL Transmission
Utilization
VS.FEGE.RxMeanSpeed/Allocat
ed bandwidth x 100%
70%
1. Transmission capacity expansion
UL Transmission
Utilization
VS.FEGE.TxMeanSpeed/Allocat
ed bandwidth x 100%
70%

ERAN Resource
eNodeB
Ethernet port
Transport
resource
group
LBBP CPU
Main-control-
board CPU
Paging
Resource
Traffic Volume
License
Connected
user license
cell
PDCCH
resource
PRACH
resource
Synchronized
user capacity
Physical
resource
block

eNode B Resource
Resource Connected user license
Meaning The connected user license specifies the maximum permissible number of users in RRC_CONNECTED mode. Each
connected user consumes radio, device, and transport resources.
If there are too many connected users, they cannot be well served by the eNodeB and new services cannot be admitted.
Counter L.Traffic.User.Avg : indicates the average number of connected users in a cell. SUM (L.Traffic.User.Avg) indicates the sum
of the average number of connected users in all cells in an eNodeB
The licensed number of connected users under an eNodeB can be queried by running the following command:
DSP LICENSE: FUNCTIONTYPE=eNodeB;
In the command output, the value of LLT1ACTU01 in the Allocated column is the licensed number of connected users
Monitoring Method Connected user license usage = SUM (L.Traffic.User.Avg)/Licensed number of connected users x 100%
Threshold 60%
Impact New services cannot be admitted, and experience of admitted users is affected.
SW/HW SW
Solution If the main-control-board CPU usage is less than 60%, increase the licensed limit.
If the main-control-board CPU usage reaches or exceeds 60%, add an eNodeB.

eNode B Resource
Resource Traffic volume license
Meaning When the traffic volume of an eNodeB reaches or exceeds the licensed volume, the eNodeB performs flow control,
which affects user experience and customer income.
Counter L.Thrp.bits.UL & L.Thrp.bits.DL: indicate the uplink traffic volume and downlink traffic volume of a cell, respectively.
Σ(L.Thrp.bits.UL+L.Thrp.bits.DL) indicates the sum of uplink and downlink traffic volume of all cells under an
eNodeB
The licensed eNodeB traffic volume can be queried by running the following command:
DSP LICENSE: FUNCTIONTYPE=eNodeB;
The licensed eNodeB traffic volume is equal to the Allocated parameter value in the record whose License Identifier
is LLT1THRUL01.
Monitoring Method Traffic volume license usage of an eNodeB = Σ(L.Thrp.bits.UL+L.Thrp.bits.DL)/(Licensed eNodeB traffic volume x
3600) x 100%
Threshold 80%
Impact User experience and customer income are affected.
SW/HW SW
Solution Increase the licensed traffic volume.

eNode B Resource
Resource Paging Resource
Meaning The eNodeB and BTS3202E or BTS3203E LTE can process a maximum of 750 and 500 paging messages per
second, respectively. If the number of paging messages exceeds that capacity, paging messages sent from the
eNodeB to UEs may be discarded, which leads to a decrease in the call completion rate.
Counter L.Paging.S1.Rx :indicates the number of paging messages received over the S1 interface
L.Paging.Dis.Num : indicates the number of paging messages discarded over the Uu interface
Monitoring Method Percentage of paging messages received over the S1 interface = L.Paging.S1.Rx/3600/Maximum number of
paging messages that can be processed per second x 100%
Threshold Percentage of paging messages received over the S1>60% (or)
L.Pagind.Dis.Num >1500
Impact Paging messages may be lost, affecting user experience.
SW/HW SW
Solution Decrease the number of cells in the tracking area list (TAL) that the congested cell belongs to.
Adjust the paging policy of the core network to reduce signaling overhead.
If the core network is provided by Huawei, enable the precise paging function.

eNode B Resource
Resource Main-control-board CPU
Meaning The CPU usage reflects the busy level of the eNodeB. If the main-control-board CPUs are busy processing control plane or user
plane data, signaling-related KPIs may deteriorate, and users may experience a low access success rate, low E-RAB setup success
rate, or high service drop rate.
Counter VS.Board.CPUload.Mean : indicates the average main-control-board CPU usage
VS.Board.CPULoad.CumulativeHighloadCount : indicates the number of times that the main-control-board CPU usage reaches or
exceeds a preconfigured threshold.
Monitoring Method Percentage of times that the main-control-board CPU usage reaches or exceeds a preconfigured threshold (85%) =
VS.Board.CPULoad.CumulativeHighloadCount/(3600/5) x 100%
Threshold Percentage of times that the main-control-board CPU usage reaches or exceeds a preconfigured threshold (85%) >5% (or)
VS.Board.CPUload.Mean >60%
Impact KPIs deteriorate.
SW/HW HW
Solution If a neighboring eNodeB is lightly loaded, adjust the antenna downtilt angles or decrease the transmit power of the local eNodeB
to shrink the coverage area and reduce the CPU load of the local eNodeB. In addition, expand the coverage area of the
neighboring eNodeB for load balancing.
If the main control board is an LMPT, replace it with a UMPT.
Add eNodeBs.

eNode B Resource
Resource LBBP CPU
Meaning If the eNodeB receives too much traffic volume, which is expressed either in bit/s or packet/s, the LBBP CPU
responsible for user plane processing is heavily loaded. As a result, the eNodeB has a low RRC connection setup
success rate, low E-RAB setup success rate, low handover success rate, and high service drop rate.
Counter VS.Board.CPUload.Mean : indicates the average LBBP CPU usage
VS.Board.CPULoad.CumulativeHighloadCount : indicates the number of times that the LBBP CPU usage reaches or
exceeds a preconfigured threshold.
Monitoring Method Percentage of times that the LBBP CPU usage reaches or exceeds a preconfigured threshold (85%) =
VS.Board.CPULoad.CumulativeHighloadCount/(3600/5) x 100%
Threshold Percentage of times that theLBBP CPU usage reaches or exceeds a preconfigured threshold (85%) >5% (or)
VS.Board.CPUload.Mean >60%
Impact KPIs deteriorate.
SW/HW HW

eNode B Resource
Solution If the LBBP is an LBBPc, replace the LBBPc with an LBBPd
Add an LBBP to share the network load, and then determine whether to move existing cells or add new cells based on
the number of UEs. The capacity expansion methods are as follows:
− If the radio resources are sufficient (that is, the usage of each type of radio resources is lower than the threshold),
move cells from the existing LBBP to the new LBBP.
- If the radio resources are insufficient, set up new cells on the new LBBP
If the eNodeB has multiple LBBPs and one of them is overloaded, move cells from the overloaded LBBP to an LBBP
with a lighter load.
LBBP load can be indicated by the following:
− Average CPU usage
− Percentage of times that the CPU usage reaches or exceeds a preconfigured threshold
− Number of cells established on an LBBP
If the eNodeB already has a maximum of six LBBPs and more LBBPs are required, add an eNodeB.

eNode B Resource
Resource Transport Resource Group
Meaning A transport resource group carries a set of data streams, which can be local data or forwarded data.
Local data is classified into control plane, user plane, operation and maintenance (OM), and IP clock
data. Forwarded data is not divided into different types. If a transport resource group is congested, it
cannot transmit or forward data, which affects service provision.
A transport resource group for user plane data is a monitored object.
Counter VS.RscGroup.TxMeanSpeed : indicates the average transmission rate of a transport resource group
VS.RscGroup.TxMaxSpeed indicates the maximum transmission rate of a transport resource group
The bandwidth configured for a transport resource group can be queried by running the following
command:
DSP RSCGRP: CN=x, SRN=x, SN=x, BEAR=xx, SBT=xxxx, PT=xxx;
In the command output, the value of Tx Bandwidth is the bandwidth configured for the transport
resource group.
Monitoring
Method
Proportion of the average transmission rate to the configured bandwidth =
VS.RscGroup.TxMeanSpeed/Bandwidth configured for the transport resource group x 100%
Proportion of the maximum transmission rate to the configured bandwidth =
VS.RscGroup.TxMaxSpeed/Bandwidth configured for the transport resource group x 100%
Threshold Mean > 80 in 5days a week, Max >90 in 2 days a week
Impact Packets may be lost, affecting user experience.
SW/HW SW
Solution When a transport resource group is congested, you are advised to expand the bandwidth of the
transport resource group

eNode B Resource
Resource Ethernet port
Meaning The Ethernet port traffic is the channel traffic at the physical layer, including uplink and downlink
traffic. The eNodeB Ethernet port traffic reflects the throughput and communication quality of the
Ethernet ports on the main control board of the eNodeB. Based on the monitoring results, you can
determine whether the transmission capacity allocated by an operator for the S1 and X2 interfaces on
the eNodeB meet the requirements for uplink and downlink transmissions.
Counter VS.FEGE.TxMeanSpeed : indicates the average transmission rate of an Ethernet port
VS.FEGE.TxMaxSpeed indicates the maximum transmission rate of an Ethernet port
VS.FEGE.RxMeanSpeed indicates the average reception rate of an Ethernet port
VS.FEGE.RxMaxSpeed indicates the maximum reception rate of an Ethernet port.
Monitoring
Method
Proportion of the average uplink transmission rate to the allocated bandwidth =
VS.FEGE.TxMeanSpeed/Allocated bandwidth x 100%
Proportion of the maximum uplink transmission rate to the allocated bandwidth =
VS.FEGE.TxMaxSpeed/Allocated bandwidth x 100%
Proportion of the average downlink reception rate to the allocated bandwidth =
VS.FEGE.RxMeanSpeed/Allocated bandwidth x 100%
Proportion of the maximum downlink reception rate to the allocated bandwidth =
VS.FEGE.RxMaxSpeed/Allocated bandwidth x 100%
Threshold Proportion of average transmission rate to allocated bandwidth ≥ 70% or
Proportion of max transmission rate to allocated bandwidth ≥ 85%
Impact Packets may be lost, affecting user experience.
SW/HW SW
Solution Expand the eNodeB transmission capacity.

Cell Resource
Resource Physical Resource Block (PRB)
Meaning Growing traffic leads to a continuous increase in PRB usage. When the PRB usage approaches to 100%,
user-perceived rates will decrease. As downlink is a major concern in an LTE network, this document
describes only how to monitor downlink user perception.
Counter L.ChMeas.PRB.DL.Used.Avg : indicates the average number of used downlink PRBs
L.ChMeas.PRB.DL.Avail : indicates the number of available downlink PRBs
L.Thrp.bits.DL : indicates the total throughput of downlink data transmitted at the PDCP layer in a cell.
L.Thrp.Time.DL indicates the duration for transmitting downlink data at the PDCP layer in a cell
Monitoring Method Downlink PRB usage = L.ChMeas.PRB.DL.Used.Avg/L.ChMeas.PRB.DL.Avail x 100%
Downlink user-perceived rate (Mbit/s) = L.Thrp.bits.DL/L.Thrp.Time.DL/1000
Threshold Downlink PRB usage ≥ 70%
Downlink user-perceived rate < a user-defined threshold (default value: 2 Mbit/s)
Impact Users may fail to be admitted, and experience of admitted users is affected.
SW/HW SW
Solution If the cell spectral efficiency is low, you are advised to increase the cell throughput by optimizing RF
performance
If the cell spectral efficiency is high, you are advised to:
− Add carriers or expand the bandwidth of the existing carrier.
− Add eNodeBs.

Cell Resource
Resource Synchronized user capacity
Meaning When the number of synchronized users in a cell reaches or exceeds a preconfigured
threshold, cell KPIs deteriorate. Connected users include synchronized users and users in
the out-of-synchronization state. Synchronized users consume air interface resources and
the number of synchronized users is approximately equal to the number of connected
users by default. Therefore, the number of connected users (instead of synchronized
users) is monitored.
Counter L.Traffic.User.Avg indicates the average number of connected users in a cell.
Monitoring Method Synchronized user capacity usage of a cell = L.Traffic.User.Avg/Maximum number of
synchronized users in a cell x 100%
Threshold 60%
Impact User experience is affected.
SW/HW HW
Solution Reduce the UE inactivity timer length by running the MOD RRCCONNSTATETIMER
command with the UeInactiveTimer parameter specified. This measure lifts signaling
overhead and increases CPU usage.
If a neighboring cell is lightly loaded, adjust the antenna downtilt angle or decrease the
transmit power of the local cell to shrink the coverage area and reduce the number of
users in the local cell. In addition, expand the coverage area of the neighboring cell for
load balancing.
Add cells or expand the cell bandwidth.
Split the local cell into multiple cells.

Resource Physical random access channel (PRACH) resource
Meaning The PRACH transmits preambles during random access procedures.
If the number of contention-based random access attempts in a second reaches or exceeds N, the
preamble conflict probability and access delay increase. The values of N are determined during
preamble design, considering factors such as that the preamble conflict probability should be less
than 1%.
If more than 100 non-contention-based random access attempts are initiated per second, dedicated
preambles will become insufficient and the eNodeB will instruct the UE to initiate contention-based
random access instead, increasing the access delay for the UE. In handover scenarios, the handover
procedure is prolonged.
Counter L.RA.GrpA.Att indicates the number of times that random preambles in group A are received.
L.RA.GrpB.Att indicates the number of times that random preambles in group B are received.
L.RA.Dedicate.Att indicates the number of times that dedicated preambles are received
Monitoring Method Random preamble usage = (L.RA.GrpA.Att + L.RA.GrpB.Att)/3600/N x 100%
Dedicated preamble usage = L.RA.Dedicate.Att/3600/100 x 100%
Threshold Usage of preambles for contention-based access ≥ 75%
Impact Access delays are prolonged, or even access attempts fail.
SW/HW SW
Solution - If the random preamble usage reaches or exceeds 75% for X days (three days by default) in a
week, enable the adaptive backoff function.
If the system bandwidth is 5 MHz or 10 MHz, it is good practice to enable the PRACH resource
adjustment algorithm
- If the dedicated preamble usage reaches or exceeds 75% for X days (three days by default) in a
week, enable the PRACH resource adjustment algorithm and reuse of dedicated preambles
Cell Resource

Resource PDCCH Resource Usage
Meaning This capacity indicator measures the number of control channel elements (CCEs) that can be used by the PDCCH.
In each radio frame, CCEs must be allocated to uplink and downlink UEs to be scheduled and common control signaling.
PDCCH CCEs must be properly configured and allocated to minimize downlink control overheads as well as to ensure
satisfactory user-plane throughput.
Counter L.ChMeas.CCE.CommUsed indicates the number of PDCCH CCEs used for common signaling.
L.ChMeas.CCE.ULUsed indicates the number of PDCCH CCEs used for uplink scheduling.
L.ChMeas.CCE.DLUsed indicates the number of PDCCH CCEs used for downlink scheduling.
L.ChMeas.CCE.Avail indicates the number of available PDCCH CCEs.
Monitoring Method CCE usage = (L.ChMeas.CCE.CommUsed + L.ChMeas.CCE.ULUsed + L.ChMeas.CCE.DLUsed)/3600/1000/Max number of
PDCCH CCEs x 100%
Threshold 80%
Impact - If PDCCH symbols are insufficient, CCEs may fail to be allocated to UEs to be scheduled, which will result in a long
service delay and unsatisfactory user experience.
- If PDCCH symbols are excessive, which indicates that the usage of PDCCH CCEs is low, the resources that can be used
by the PDSCH decreases. This will also result in low spectral efficiency.
SW/HW SW
Solution If the PDCCH Symbol Number Adjust Switch parameter value is Off, you are advised to set this parameter to On
If the PDCCH Symbol Number Adjust Switch parameter value is set to On and the uplink or downlink PRB usage reaches
or exceeds 70%, you are advised to take one of the following measures:
- Add cells or split existing cells.
− Optimize RF performance to reduce the interference to PDCCH from neighboring cells.
Cell Resource

References - LBBP
Board
Number of Cells
Cell Bandwidth Antenna
Configuration
LBBPc
3
1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, or
20 MHz
3x20 MHz 1T1R
3x20 MHz 1T2R
3x10 MHz 4T4R
3x20 MHz 2T2R
1x20 MHz 4T4R
LBBPd1
3
20 MHz
3x20 MHz 1T1R
3x20 MHz 1T2R
3x20 MHz 2T2R
LBBPd2
3
20 MHz
3x20 MHz 1T1R
3x20 MHz 1T2R
3x20 MHz 2T2R
3x20 MHz 4T4R
LBBPd3
6
20 MHz
6x20 MHz 1T1R
6x20 MHz 1T2R
6x20 MHz 2T2R
a
a: When a CPRI fiber optic cable is longer than 40 km (24.85 mi), the LBBPd3 board cannot support the 6x20 MHz 2T2R
channel.
Board Signaling Specification (CAPS)
LBBPc 30
LBBPd1, LBBPd2,
LBBPd3, and
LBBPd4
60
Board Cell Bandwidth Maximum Number of UEs
in RRC Connected Mode
LBBPc 1.4 MHz 1008
3 MHz 1800
5 MHz 1800
10 MHz 1800
15 MHz 1800 (in 2R mode) or 1200
(in 4R mode)
20 MHz 1800 (in 2R mode) or 1200
(in 4R mode)
LBBPd1/LBBPd2 1.4 MHz 504
3 MHz 1080
5 MHz 1800
10 MHz 3600
15 MHz 3600
20 MHz 3600
LBBPd3 1.4 MHz 1008
3 MHz 2160
5 MHz 3600
10 MHz 3600
15 MHz 3600
20 MHz 3600
Board Maximum Throughput
LBBPc Downlink: 300 Mbit/s
Uplink: 100 Mbit/s
LBBPd1 Downlink: 450 Mbit/s
Uplink: 225 Mbit/s
Uplink: 225 Mbit/s
Uplink: 300 Mbit/s
Uplink: 225 Mbit/s
Antenna Config
Throughput
Signalling
RRC Connected Mode

References - LBBP
RACH algorithm
switch
Bandwidth N
- 15,20 100
Enable 5,10 100
Disable 5,10 50
PRACH PDCCH

Thank you
www.huawei.com
Copyright©2011 Huawei Technologies Co., Ltd. All Rights Reserved.
The information in this document may contain predictive statements including, without limitation, statements regarding the future financial
and operating results, future product portfolio, new technology, etc. There are a number of factors that could cause actual results and
developments to differ materially from those expressed or implied in the predictive statements. Therefore, such information is provided for
reference purpose only and constitutes neither an offer nor an acceptance. Huawei may change the information at any time without notice.

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