Capacity monitoring

Network Resources
Capacity monitoring methods
Capacity monitoring methods: 2) Problem driven analysis:
1) Daily monitoring : • Problem caused by congestion
• Counters for usage resources • Problems are accurately
• Threshold for resources located
• Prevent network congestion
Cell resources
1) PRB (physical resource block) :
• PRBs used for resource allocation (time,frequency).
• BW consumed in air interface
• Depends on traffic , when traffic increases it requires more PRB usage
so data rate decreases
• When PRB usage > 70% && rate < 2Mbit/sec
• Soln : Add carriers (SE is low) , optimize Rf performance (SE is high)
Cell resources
2) Synchronized user capacity :
• Multiple devices need to maintain synchronization with the network
• Connected users = synch users
• Number of connected users / max number of connected users for a
cell
• Soln : Reduce the UE inactivity timer length , 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.
Cell resources
3) PRACH resource usage
• Transmit preambles in random access (contention , non contention)
• Preamble : no. of bits used when a device sense a medium and the
medium is busy so this device send a preamble to intent that it will
transmit (random , dedicated)
• Random preamble used for initial access transmitted by UE to
establish a connection with network
• Dedicated preamble used when connection with network is
established and network assign a specific preamble for UE to
communicate
Cell resources
• Cases
1) Random preamble usage > 75%
Soln : enable adaptive backoff function (note : if BW is 5,10 MHZ enable
resource adjustment algorithm)
2) Dedicated preamble > 75%
Soln : enable resource adjustment algorithm
Adaptive backoff function : There is a backoff timer before sending
data, adaptive to change the predetermined timer value to avoid
collision and it’s based on network condition like network congestion
Cell resources
Resource adjustment algorithm : optimize the allocation of resources
like power and BW

This helps reduce the probability of UEs initiating contention-based

random access in the case of dedicated preamble insufficiency and
therefore helps reduce the access delay.
Cell resources
4) PDCCCH
• Measures the number of control channel elements (CCEs) that can be used by the PDCCH.
• CCEs must be allocated to uplink and downlink UEs to be scheduled
1. Uplink Scheduling: Uplink scheduling involves deciding which UEs are granted access to the network to
transmit data from the UEs to the base station
2. Downlink Scheduling: downlink scheduling involves deciding which UEs will receive data from the base
station.
1) If PDCCH symbols are insufficient, CCEs may fail to be allocated to UEs to be scheduled which will lead to
increase in delay
Scheduling : when and how resources (BW , timeslots) are allocated for UEs in network
2) If PDCCH symbols are excessive which indicates low usage of CCEs so the resources will not be allocated
for UEs so the resources can be used for PDSCH (data channel) will decrease that indicates low spectral
effeciency
EnodeB resources
1) Connected user license usage
• Max number of users in RRC connected mode (actively connected with the network)
• RRC : is a protocol used in 3GPP to control radio resources and manage the connection between
UE and RAN
• If connected user > = 60 %
if CPU usage < 60% -> increase license usage
if CPU usage > 60 -> add enodeB
EnodeB resources
2) Traffic volume license usage
• When the traffic volume of an eNodeB reaches or exceeds the licensed volume, the eNodeB performs flow
control.
• Flow control involves mechanisms and techniques to regulate the flow of data between two
communicating devices or entities within a network. The primary purpose of flow control is to
ensure that data is transmitted at a rate that the receiving device can handle, preventing
congestion and data loss
• If the traffic volume license usage of an eNodeB reaches or exceeds 80% , you are advised to increase the
licensed traffic volume.
EnodeB resources
3) Paging resource usage
• Paging used for location update for UE used when there is an
incoming call for this UE
• leads to a decrease in the call completion rate.
If the percentage of paging messages received by the eNodeB over the S1 interface reaches or
exceeds 60%
• soln : Decrease the number of cells in the tracking area list (TAL) that the congested cell belongs
to so Ues are required to update their tracking area information less frequently
• Enable the precise paging function if core network is Huawei
EnodeB resources
4) CPU usage
1. 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
Signaling KPIs: Signaling KPIs include various metrics that measure the performance of signaling
processes in the network. These KPIs often cover a range of activities, including network access, call
setup, handovers, and other control plane procedures.
Deterioration: Means a decline or worsening in the performance of these KPIs
Access Success Rate: The access success rate measures the ability of UEs to successfully access the
network.
• If the MCS measurement indicate that the channel quality is poor, KPI deterioration may not be
caused by main-control-board CPU overload but by deterioration in channel quality.
• If the KPIs deteriorate and the main-control-board CPU usage exceeds a preconfigured threshold so
it’s due to CPU usage
EnodeB resources

1) The average main-control-board CPU usage reaches or exceeds 60%.

2) The percentage of times that the main-control-board CPU usage reaches or exceeds 85% is
greater than or equal to 5%.
Take one of the following measures:
• 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.
EnodeB resources
5) Baseband CPU usage
• If the eNodeB receives too much traffic volume, which is expressed either in bit/s or packet/s, the
baseband processing unit CPU responsible for user plane processing is heavily loaded
• Leads to low RRC connection setup success rate, low E-RAB setup success rate, low handover success
rate.
• E-RAB (Evolved Radio Access Bearer(channel)) setup success rate is a key performance indicator (KPI)
in cellular networks. It measures the percentage of successful establishment of dedicated radio
bearers used for transmitting user data and signaling between the user equipment (UE) and the
network's base station.
• An E-RAB is a logical connection that is established between a user equipment (UE), such as a mobile phone or
a data terminal, and the core network (CN) through the radio access network (RAN). It is used to carry user data
and signaling information between the UE and the network.
• A low E-RAB setup success rate indicates that there are difficulties in setting up dedicated bearers for
data transmission
Baseband processing unit load can be indicated by the following:
1) Average CPU usage
2) Percentage of times that the CPU usage reaches or exceeds a preconfigured threshold
3) Number of cells established on a baseband processing unit
Soln:
• If the baseband processing unit is an LBBPc, replace the LBBPc with an LBBPd.
• Add a baseband processing unit to share the network load, and then determine whether to move existing cells
or add new cells.
• If the radio resources are sufficient move cells from the existing baseband processing unit to the new
baseband processing unit.
• If the radio resources are insufficient, set up new cells on the new baseband processing unit.
• If the eNodeB has multiple baseband processing units and one of them is overloaded, move cells from the
overloaded baseband processing unit to a baseband processing unit with a lighter load
• If the eNodeB already has a maximum of six baseband processing units and more baseband processing units
are required, add an eNodeB.
EnodeB resources
6) Transport resource usage
• 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.
EnodeB resources
• A transport resource group is congested if one of the following conditions is met:
1) The proportion of the average transmission rate to the configured bandwidth reaches or exceeds 80%
2) The proportion of the maximum transmission rate to the configured bandwidth reaches or exceeds 90%
• When a transport resource group is congested, you are advised to expand the bandwidth of the transport
resource group.
• If the problem persists after the bandwidth adjustment, you are advised to expand the eNodeB bandwidth.
EnodeB resources
7) Ethernet Port Traffic
• 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.
• Perform transmission capacity expansion if either of the following conditions is met:
1) The proportion of the average uplink transmission rate (or downlink reception rate) to the allocated
bandwidth reaches or exceeds 70% .The allocated bandwidth is 750 Mbit/s by default. The actually
allocated bandwidth can be obtained from the operator.
2) The proportion of the maximum uplink transmission rate (or downlink reception rate) to the allocated
bandwidth reaches or exceeds 85%
Soln : extend BW
Appendix
• PRACH Resource Usage
1) To check whether the PRACH resource adjustment algorithm is enabled, run the LST
CELLALGOSWITCH command to query the value of the RachAlgoSwitch.
2) Enable the adaptive backoff function by running the following command to help reduce the peak RACH load
and average access delay:
MOD CELLALGOSWITCH: LocalCellId=x, RachAlgoSwitch=BackOffSwitch-1
3) Enable the PRACH resource adjustment algorithm by running the following command:
MOD CELLALGOSWITCH: LocalCellId=x,RachAlgoSwitch=RachAdjSwitch-1;
4) Enable the PRACH resource adjustment algorithm and reuse of dedicated preambles between UEs by
running the following command:
MOD CELLALGOSWITCH: LocalCellId=x,RachAlgoSwitch= RachAdjSwitch-
1,RachAlgoSwitch=MaksIdxSwitch-1;
Appendix
PDCCH Resource usage
The number of PDCCH symbols depends on the PDCCH Symbol Number Adjust Switch parameter value,
which can be queried by running the LST CELLPDCCHALGO command:
If the parameter value is On, the number of PDCCH symbols is 3.
If the parameter value is Off, the number of PDCCH symbols is equal to the PDCCH Initial Symbol Number
parameter value, which can be queried by running the LST CELLPDCCHALGO command.
The value of Ng is equal to the PHICH resource parameter value, which can be queried by running the LST
PHICHCFG command.
If the PDCCH Symbol Number Adjust Switch parameter value is Off, you are advised to set this parameter to
On by running the following command:
MOD CELLPDCCHALGO: LocalCellId=x, PdcchSymNumSwitch=ON;
Appendix
Appendix
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.
Appendix
• Connected user license
The licensed number of connected users 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.
Appendix
• Traffic Volume License Usage
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
Appendix
• Transport Resource Group Usage
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.

When a transport resource group is congested, you are advised to expand the bandwidth of the transport
resource group. The following is an example command:
MOD RSCGRP: CN=x, SRN=x, SN=x, BEAR=IP, SBT=BASE_BOARD, PT=ETH, PN=x,
RSCGRPID=x, RU=x, TXBW=xxxx, RXBW=xxxx;
Appendix
• Ethernet Port Traffic
You can run the LST LR command to query the values of LR Switch, UL Committed Information Rate
(Kbit/s), and DL Committed Information Rate (Kbit/s).
The types of main control boards can be queried by running the following command:
DSP BRD: CN=x, SRN=x, SN=x;
In the command output, the value of Config Type is the type of the main control board.