The document discusses PCI (Physical Cell Identity) planning in LTE networks. It describes the cell search process where the UE detects the PCI from the PSS and SSS. The PCI is used to determine the location of reference signals and avoid interference. The document recommends strategies for PCI planning such as assigning color groups to sectors and code groups to sites to avoid conflicting PCI combinations in adjacent cells. It also discusses tools to analyze potential PCI interference and make changes to mitigate issues.
The document discusses mobility management in LTE networks. It covers connected mode mobility including an overview of mobility triggers and handover thresholds, measurement configuration, intra-frequency handovers, inter-frequency handovers, and inter-RAT handovers. It also discusses idle mode mobility including system information blocks and cell selection procedures for intra-frequency, inter-frequency, and inter-RAT mobility. The presentation provides details on the different mobility management procedures and configuration parameters in LTE networks.
This document is a master report on WCDMA RF optimization that provides information and solutions for analyzing and resolving problems in the RF part of a WCDMA network. It discusses basic processes for RF optimization including optimizing signal coverage and controlling pilot pollution. It also covers network problem analysis, the work process used, and data collection tools and techniques. The report aims to present a manual for UMTS data collection and optimization based on experiences from the UAE Etisalat network.
The document discusses UMTS planning and dimensioning processes. It describes:
1) The overall planning process which includes system dimensioning, radio network planning, pre-launch optimization, performance monitoring, and post-launch optimization.
2) The inputs, assumptions, and steps used for air interface dimensioning which includes uplink and downlink link budget analysis to determine coverage requirements and capacity needs.
3) Traffic modelling and load calculation methods to estimate subscriber traffic per cell based on factors like subscriber density, traffic profiles, and cell area.
The document discusses various parameters used in LTE drive testing including:
- RSRP, RSRQ, SINR, RSSI, CQI, PCI, BLER, and throughput which provide information on signal strength, quality, and performance. Phone-based drive testing allows monitoring of these parameters and correlation with data performance. MIMO and handovers between LTE and other technologies can also be evaluated. Key metrics include coverage, capacity, and end-user experience.
The document discusses key planning parameters for TD-LTE including PRACH, PCI, and UL DM RS. It provides details on:
1) PRACH planning including separating PRACH resources by time, frequency, or sequence to reduce interference between cells.
2) Recommendations for selecting PRACH preamble formats and configuration indexes based on cell range.
3) Guidelines for configuring PRACH frequency offset, cyclic shift, and root sequence index based on factors like PUCCH resources and number of preamble sequences needed.
2 g and 3g kpi improvement by parameter optimization (nsn, ericsson, huawei) ...Jean de la Sagesse
The document discusses key performance indicators (KPIs) for 2G and 3G networks and how top telecom vendors like Ericsson, Huawei, and NSN optimize parameters to improve these KPIs. It outlines techniques for reducing TCH blocking, SD blocking, TCH drop, HOSR, TASR, SD drop, and improving paging success rate through actions like changing configuration parameters, enabling features, addressing hardware issues, and optimizing cells physically. The optimization of these parameters can help maintain balance between network throughput, capacity and radio quality while ensuring a seamless transition between 2G and 3G.
The document discusses the requirements and configuration of Inter Frequency Load Balancing (IFLB) in LTE networks. IFLB aims to balance traffic load across cells on different frequencies by offloading user equipment between those cells. Key steps in IFLB include determining cell load, exchanging load information, selecting offload candidates, and handing users over to target cells if their signal quality is sufficient. The document provides guidance on setting parameters that control IFLB behavior and thresholds.
1. The document discusses NSA mobility management for Huawei's 5G network, including procedures for adding, changing, and releasing the secondary node (SgNB).
2. Key procedures covered include SgNB addition triggered by the MeNB, intra-SgNB and inter-SgNB PSCell changes, and intra-MeNB and inter-MeNB handovers.
3. NSA mobility is anchored to the LTE network, with the eNodeB delivering NR measurement configurations and processing measurement reports.
This document discusses radio resource optimization parameters in GSM networks. It covers topics like idle parameter optimization, power control, handover control, radio resource administration, measurement processing, signaling channel mapping, traffic channel mapping, paging parameters, access grant channel parameters, frequency reuse, and frequency hopping techniques. Diagrams and examples are provided to illustrate concepts like TDMA frame structure, logical and physical channel organization, and capacity calculations.
Nokia gsm-kpi-analysis-based-on-daily-monitoring-basis-presentationmohammed khairy
This document discusses key performance indicators (KPIs) for monitoring a GSM network and reasons for and solutions to common issues. It provides relationships between different network elements and describes concepts like SD blocking, SD drop, TCH blocking, TCH assignment, TCH drop, and handover success rate (HOSR). For each KPI, it outlines potential causes for degradation and recommendations to address hardware faults, interference, parameter misconfiguration, and other problems.
Call Setup Success Rate Definition and Troubleshooting Assim Mubder
The CSSR indicates the probability of successful calls initiated by the MS. The CSSR is an important KPI for evaluating the network performance. If this KPI is too low, the subscribers are not likely to make calls successfully. The user experience is thus affected.
This document discusses various causes and troubleshooting steps related to 2G call drops and unsuccessful handovers. It addresses issues like low signal strength, interference, incorrect parameter settings, transmission faults, hardware faults, and more. The key performance indicators of TCH Drop Rate and Handover Failure Rate are defined. Causes of dropped calls on traffic channels include excessive timing advance, low signal strength, poor quality, sudden loss of connection, and other factors. Investigation steps provided include checking error logs, parameters, neighboring cell definitions, transmission quality, antenna installation, and more.
This document provides an overview and classification of interference sources in GSM networks, as well as approaches to locating interference problems. It discusses symptoms of network interference, including errors seen in traffic statistics and drive tests. Interference sources are classified as hardware faults, intra-network interference between cells, and inter-network interference from other communication systems. Methods for locating interference include analyzing OMC data, alarms, drive tests, and using spectrum analyzers to detect interfering signals. The document also provides guidance on solving common interference issues.
This document provides technical training on optimizing LTE downlink throughput. It discusses:
1. The increasing commercial adoption of LTE networks and rapid growth of LTE users.
2. Challenges in optimizing LTE networks including insufficient analysis capabilities and experience-based adjustments.
3. A proposed optimization scheme involving in-depth analysis of issues like weak coverage, interference and throughput problems to identify root causes and targeted optimization suggestions.
This document provides an overview of LTE functionalities and features. It begins with background on LTE development and standardization. It then describes the LTE network elements and interfaces, including the radio interface between UE and eNB. The document reviews the RRM framework and lists key RRM features, providing status updates on which features are ready in the current release or planned for future releases. It also includes roadmaps showing the planned features and timeline for LTE releases. The document appears to be an internal presentation on LTE technologies and the Nokia Siemens Networks product roadmap.
This document provides formulas and proposed targets for key performance indicators (KPIs) related to LTE network monitoring. It includes KPIs for LTE OSS statistics measured at the network level and LTE drive test KPIs measured through field testing. For each KPI, it provides the detailed formula, measurement methodology, and a brief description. The goal is to establish a framework for initial discussion on monitoring LTE network performance.
The document discusses the need for new wireless technologies to support increasing demand for data and high-speed services. It notes that technologies need to focus on using more spectrum, improving spectral efficiency, employing smaller cell sizes like femtocells, and incentivizing off-peak traffic. The rest of the document provides details on how LTE wireless technology addresses these needs through technical specifications and network architecture, including the use of an Evolved Packet Core and separating the user and control planes.
The document summarizes different 3G events that can trigger handover procedures in UMTS networks. It describes 7 categories of events related to primary pilot channel, frequency, quality, channel traffic volume, CRCs, Rx-Tx parameters, and location/position. Each category contains multiple specific events that are monitored and can trigger handovers based on thresholds being passed for radio frequency parameters. The events monitor factors like signal quality, interference levels, traffic loads, transmission power, and device location to determine when a UE should hand over to a better serving cell.
WR_BT03_E1_1 Channel Structure and Function-44.ppttunaVNP
The document discusses the structure and classification of channels in UMTS networks, including physical, transport and logical channels, and their mapping relationships. It also outlines the key steps in the cell search procedure used for network acquisition and synchronization, as well as an overview of the random access channel procedure.
1) The planning of Physical Cell Identities (PCI) has a strong impact on the performance of LTE networks. PCI planning determines the frequency locations of cell-specific reference signals, which can collide between neighboring cells and degrade signal quality estimates.
2) Most research on PCI planning has focused on avoiding collisions and confusion between PCI assignments. However, no study has quantified the impact of PCI planning on downlink throughput performance.
3) This paper develops an analytical model to quantify the influence of PCI planning on reference signal collisions. It then uses a system-level simulator to test different PCI planning schemes and analyze their impact on call blocking, dropping, and user throughput under various traffic conditions.
An Overview of the ATSC 3.0 Physical Layer SpecificationAlwin Poulose
ATSC 3.0 Physical Layer Specification
IEEE TRANSACTIONS ON BROADCASTING,
VOL. 62, NO. 1, MARCH 2016
Luke Fay, Lachlan Michael, David Gómez-Barquero, Nejib Ammar, and M. Winston Caldwell
1) The document outlines a 5-step process for planning Physical Cell Identity (PCI) assignments in Atoll software.
2) The steps include: creating an LTE project with site details, defining a core planning area, creating a neighbor list, running the PCI planning, and checking outputs for collisions.
3) PCI planning ensures each cell is correctly identified by assigning one of 504 unique PCI numbers while avoiding collisions in neighboring cells or when values are divided by 6.
The document discusses key aspects of synchronization signal blocks (SSBs) in 5G NR, including:
1) An SSB consists of PSS, SSS and PBCH which enable cell search and detection of physical layer cell ID.
2) SSBs are transmitted periodically with configurable periodicities and occupy 4 OFDM symbols in the time domain.
3) In the frequency domain, SSBs are transmitted on synchronization rasters called GSCNs which have wider steps than LTE to facilitate faster cell search.
Decoding of the extended Golay code by the simplified successive-cancellation...TELKOMNIKA JOURNAL
This paper describes an adaptation of a polar code decoding technique in favor of the extended Golay code. Based on the bridge provided by a permutation matrix between the code words of these two classes of codes, the Golay code can be decoded by any polar code technique. Contrary to the successive-cancellation list technique which is characterized by a serial estimation of the bits, we propose in this work an adaptation of the simplified successive-cancellation list technique to polar codes equivalent to the Golay code. The simulations have achieved the performance of a maximum likelihood decoding, with the low decoding complexity of polar codes, compared to one of the universal decoders of linear codes most known in the literature.
WiFiRe is a system that extends the range of WiFi signals to 15-20 km using sectorized directional antennas to provide broadband wireless access to rural villages in India. It uses a single WiFi channel shared across all sectors, with a WiMAX-like MAC layer to coordinate multi-sector transmissions and guarantee quality of service for voice traffic. Key benefits are low cost using off-the-shelf WiFi components without requiring wireless spectrum licensing.
lte-enodeb-s1-startup-sib-rrc-connection.pdfJunaid Alam
The document summarizes the sequence of events for an eNodeB performing an S1 setup with the EPC and then initiating broadcasts of system information blocks (SIBs) to UEs. It shows the eNodeB sending the RRC Connection Setup message containing UE specific configuration information. The eNodeB first establishes an S1 connection with the MME and then broadcasts the master information block and various SIBs. It then facilitates the random access procedure and sends the RRC Connection Setup message to the UE.
Design and implementation of log domain decoder IJECEIAES
Low-Density-Parity-Check (LDPC) code has become famous in communications systems for error correction, as an advantage of the robust performance in correcting errors and the ability to meet all the requirements of the 5G system. However, the mot challenge faced researchers is the hardware implementation, because of higher complexity and long run-time. In this paper, an efficient and optimum design for log domain decoder has been implemented using Xilinx system generator with FPGA device Kintex7 (XC7K325T-2FFG900C). Results confirm that the proposed decoder gives a Bit Error Rate (BER) very closed to theory calculations which illustrate that this decoder is suitable for next generation demand which needs a high data rate with very low BER.
Evaluation of STBC and Convolutional Code Performance for Wireless Communicat...theijes
Under rich dissipating environment, Multiple Input Multiple Output (MIMO) scheme have better performance in term of reliability and increasing the throughput. Space Time Block Code (STBC) can reduce the Bit Error Rate (BER) with suitable data rate. In order to raise the amount of throughput more, high modulation order is used but it degrade the performance. To address this problem, a Convolutional Code (CC) can be support such system with various code rate to deal with different circumstances. This research is proposed a system with serial concatenation of STBC and CC with various modulation levels. Such system is tested with Rayleigh flat and selective fading channel by Matlab package R2015b with a list of modulation order and changing the code of each STBC and CC. The results show that such system can cover a range of Signal to Noise Ratio (SNR) from 0 to 21 dB of SNR for selective fading channel and -2 to 19 dBfor flat fading channel for a targeted BER of 10-4 with a various modulation index and code rate which lead to a flexible system to change the throughput depending on user conditions.
Fast detection of number of antenna ports in lte systemeSAT Journals
Abstract
In LTE system, during initial cell selection UE is unaware about the number of antennas used by eNB for transmission. So, UE blindly tries multiple times to detect the right number of antennas used for transmission in the system. This wastes lot of time and UE processing power, as UE needs to do channel estimation, equalization/demodulation, decoding process multiple times with assumption of 1 or 2 and 4 antenna ports each time.
The objective of this paper is to find out a faster and efficient method for detecting the number of antenna ports used by the eNB for signal transmission. A new method is explored for detecting the number of eNB transmit antennas before starting PBCH decoding and CRC checking by exploiting the presence of downlink reference signals at various Resource Element (RE) positions in the Resource Blocks (RB) and using the PBCH SFBC data patterns. This helps for faster detection of number of antennas used for transmission that in turn helps to reduce the UE power consumption as well as reduces the initial cell search time.
Keywords: UE- User Equipment, LTE- Long-Term Evolution, eNB- evolved Node B, RAT- Radio Access Technology, PBCH- Physical Broadcast Channel, SFBC- Space Frequency Block Codes, DL – Down Link.
This document provides information about the CMOS VLSI Design course. It outlines the course code, credit hours, exam details, and topics to be covered. The topics include MOS transistor theory, CMOS process technology, digital CMOS design including combinational and sequential logic circuits, analog CMOS design including amplifiers, and dynamic CMOS and clocking. It also lists reference books and laboratory experiments involving digital and analog design using EDA tools. The experiments involve designing circuits like inverters, adders, counters, and completing the full ASIC design flow from schematic to layout.
1) Multibeam antennas can provide cost-efficient capacity gains but their deployment introduces new planning challenges like coverage gaps and physical cell identity (PCI) conflicts.
2) Coverage gaps may arise after upgrading to multibeam antennas if beam directions are not properly adjusted. Rotating all sectors by 10-20 degrees can eliminate gaps.
3) PCI planning is more complex with multibeam antennas due to limitations of PCI modulo 3 for reference signal allocation. Proper grouping of PCI values within and between sites can help mitigate conflicts.
The document describes a method for unambiguously characterizing 4G LTE signal coverage using PBCH (Public Broadcast Channel) decoding. It explains that by decoding the PBCH bits and checking for errors, one can positively determine signal quality without knowing the original bits. This is more decisive than conventional RSSI or RSRP metrics. The document then provides details on PBCH encoding/decoding processes and how the results (PBCH OK, PBCH poor, PBCH bad) correspond to varying levels of signal coverage and user experience. Test examples demonstrate the different PBCH decoding outcomes.
This document outlines the WCDMA physical layer design. It discusses the WCDMA network architecture and physical layer in detail. Specifically, it describes the uplink and downlink physical channels, transport channels, logical channels, spreading techniques, channelization codes, scrambling codes, and frame structure used in WCDMA. It provides information on uplink and downlink dedicated and common physical channels, and the various coding, modulation, and multiplexing schemes used in the WCDMA physical layer.
Performance evaluation of family of prime sequence codes in an ocdma systemIAEME Publication
This document analyzes and compares the performance of different families of prime sequence codes for optical code division multiple access (OCDMA) systems. It describes prime codes, modified prime codes, new modified prime codes, double padded modified prime codes, and evaluates them based on code length and code weight. Longer codes with higher code weights are found to have better correlation properties and lower bit error rates, allowing more users to be supported in the OCDMA system.
Investigating the Performance of NoC Using Hierarchical Routing ApproachIJERA Editor
The Network-on-Chip (NoC) model has appeared as a revolutionary methodology for incorporatingmany number of intellectual property (IP) blocks in a die. As said by the International Roadmap for Semiconductors (ITRS), it is must to scale down the device size. In order to reduce the device long interconnection should be avoided. For that, new interconnect patterns are need. Three-dimensional ICs are proficient of achieving superior performance, resistance against noise and lower interconnect power consumption compared to traditional planar ICs. In this paper, network data routed by Hierarchical methodology. We are analyzing total number of logic gates and registers, power consumption and delay when different bits of data transmitted using Quartus II software.
Investigating the Performance of NoC Using Hierarchical Routing ApproachIJERA Editor
The Network-on-Chip (NoC) model has appeared as a revolutionary methodology for incorporatingmany number of intellectual property (IP) blocks in a die. As said by the International Roadmap for Semiconductors (ITRS), it is must to scale down the device size. In order to reduce the device long interconnection should be avoided. For that, new interconnect patterns are need. Three-dimensional ICs are proficient of achieving superior performance, resistance against noise and lower interconnect power consumption compared to traditional planar ICs. In this paper, network data routed by Hierarchical methodology. We are analyzing total number of logic gates and registers, power consumption and delay when different bits of data transmitted using Quartus II software.
I studied in Indian Institute of Technology, Kharagpur, India. I did my B.Texh and M.Tech in the department of Electronics and Electrical Communication Engineering. I was student of 2018 batch. After that, I joined Schneider Electric Systems India Private limited Company as Software design Engineer. Currently I am designated as Senior Firmware Engineer in the same company. I have work experience of 4+ years. The uploaded ppt is my MTP Thesis. It is about "temperature aware application mapping on to mesh based network on chip using Genetic Algorithm".
The document discusses number systems and coding schemes. It describes how to convert between decimal, binary, octal, hexadecimal and other number systems. It also discusses various coding schemes like binary coded decimal, excess-3 code, gray code, alphanumeric codes and complements. The key points are:
1) A number system with base 'r' contains 'r' different digits from 0 to r-1. Decimal to other bases conversions involve dividing the integer part by the base and multiplying the fractional part by the base.
2) Coding schemes discussed include binary coded decimal (BCD), excess-3 code, gray code, alphanumeric codes like EBCDIC.
3) Complements like 1's complement
Paulo Campolina Resume - Sr RF Engineer 09182016paulo_campolina
Paulo Campolina has over 26 years of experience in telecommunications, specializing in RF engineering for LTE, UMTS, and GSM networks. He has held senior engineering roles at Ericsson, Nokia, and telecom operators in the US and Brazil, leading projects, teams, and providing expertise in radio network design, optimization, and quality control. Paulo has extensive experience managing all phases of wireless network development from initial planning and design through launch, optimization, and maintenance.
Este documento apresenta uma introdução sobre a história da transmissão de rádio, desde as primeiras invenções do telégrafo por Samuel Morse até as experiências pioneiras de Marconi com ondas de rádio. Também descreve conceitos básicos como o sinal eletromagnético e sua propagação através do espaço livre e da atmosfera terrestre, além de mecanismos como reflexão e desvanecimento que afetam a propagação.
O documento discute os efeitos do VSWR (Voltage Standing Wave Ratio) na potência transmitida, explicando que um baixo VSWR não significa necessariamente que o sistema esteja correto e que atenuações na linha de transmissão podem mascarar problemas de impedância. Também mostra como o VSWR é afetado por perdas e como pequenas diferenças de VSWR não resultam em ganhos significativos de potência.
Este documento discute unidades de medida comumente usadas em telecomunicações, como decibel (dB), dB relativo (dBr), dBm e dBmO. Explica que dB representa a relação logarítmica entre potências de entrada e saída, enquanto dBm é relativo a 1 mW. Também fornece exemplos de como calcular ganhos, atenuações e potências usando estas unidades.
1. O documento discute a análise de propagação de ondas de rádio segundo a teoria de Fresnel, apresentando conceitos como zonas de Fresnel, elipsóides de Fresnel e cálculos geométricos de pontos típicos da elipse.
2. A teoria de Fresnel estabelece que as zonas de Fresnel são elipsóides concêntricos com eixo principal na linha de visada entre a antena transmissora e receptora. A primeira zona de Fresnel define a área onde o sinal precisa ser desimped
2. Page 2
LTE Cell Search Description PCI
• Cell search is the first procedure executed by an UE (User Equipment) to connect to the LTE network.
• After tuning on the strongest frequency channel depending upon which bands it is supporting.
• This procedure demands the synchronization of radio symbols and frames between the UE and the
eNodeB.
• To achieve that, two synchronization signals are broadcasted by the eNodeB every 10 ms:
• Primary Synchronization Signal, PCI- ID (PSS)
It is present in subframes 0 and 5 (OFDM symbol 6) and is mapped on 72 subcarriers in the middle of
the band. From PSS, the UE is also able to obtain physical layer identity (0 to 2).
It is used to detect the carrier frequency and the SCH symbol timing.
• Secondary Synchronization Signal, PCI- group (SSS)
It is present in subframe 0 and 5 (OFDM symbol 5), and is also mapped on 72 subcarriers in the middle
of the band. The SSS is 168 sequence number (0 to 167).
It is used to synchronize the UE to the frame timing.
One frame (10 ms)
PSS SSS
6 resource blocks
(72 center sub-carriers)
3. Page 3
LTE Cell Search Description PCI
• Using physical layer identity and cell identity group number, the UE knows the PCI for this cell now.
• In LTE 504 physical layer cell identities (PCI) are allowed and are divided into unique 168 cell layer identity
groups where each group consist of three physical layer identity.
• As mentioned earlier, UE detects physical layer identity from PSS and physical layer cell identity group from
SSS. Assuming physical layer identity = 1 and cell identity group=2 then the PCI for given cell is
• PCI = 3*(Physical layer cell identity group)+ physical layer identity = 3*2+1 = 7
• Once the UE knows the PCI for a given cell, it also knows the location of cell Reference signals as shown in
figure (red and black squares). Reference signals are used in channel estimation, cell selection / reselection
and handover procedures.
• The figure shows the CRS pattern in time and frequency for one
Physical Resource Block (PRB) and Transmission Time Interval
(TTI) with the normal cyclic prefix.
• The squares represent the Resource Elements (REs), each one
consisting of a combination of a subcarrier and an OFDM
Symbol.
• The CRSs are always transmitted in the same OFDM symbol for
all PRBs in the cell, regardless of PCI value.
• But in the Frequency Domain, the value of The PCI defines the
frequency shift of CRSs from a limited set of values, defined by :
• Function MOD-6 of the PCI (One antenna port)
• Function MOD-3 of the PCI (Two or four antenna ports)
5. Page 5
Detection of carrier frequency
Detection of SCH symbol timing
Identification of cell ID (0-2)
Detection of radio frame timing
Detection of cell ID group (0-167) PCI
Detection of MIMO & CP configuration
PSS
SSS
Read System Info & RS
timing
sequence
frequency shift
LTE Cell Search Description PCI
6. Page 6
PCI Planning PCI
For each cell, PCIi = 3Sj + Pk
i = 0 … 503
j = 0 … 167 group
k = 0 … 2 ID
The sequence for the SSS signal is generated as follows:
m0 = m’ mod 31
m1 = [m0+INT(m’/31)+1] mod 31
m’ = Sj+q(q+1)/2
q = INT((Sj+q’(q’+1)/2)/30); q’ = INT(Sj/30)
Simulations hint that the following combinations at adjacent cells will give bad performance, i.e. long
synchronization times and high interference:
Same ID, i.e. same k
Same m0
Same m1
For example, PCIi = 0 PCIi = 3, 6, … 498, 501 and 1, 2, 90, 91, 92, 177, 178, 179, 261, 262, 263, 342, 343,
344, 420, 421, 422, 495, 496, 497 are not optimal combinations for adjacent cells. This is valid for the case
when cells are synchronized.
Group #0
PCI0
PCI2PCI1
Group #1
PCI3
ID5PCI4
Group #2
PCI6
PCI8PCI7
Group #167
PCI501
PCI503PCI502
7. Page 7
• The number of possible patterns of pilot (CRS) depends on the antenna configuration, but it is less than 6.
• CRS collision degrades the SINR estimation reported by the UE to the eNodeB, and affects the modulation
and coding schemes (MCS) for downlink transmission.
• An eNodeB should be PCI collision and confusion free.
• Collision free PCI means that two adjacent cells do not have same PCI
• Confusion free PCI means that a cell may not have neighbors with same PCI
• Also, frequency shift plays an important role during the PCI assignment. The PCI itself gives the frequency
shift through the formula below
P0 = PCI mod 6 + k.6
P1 = (PCImod6) mod3 +k.6 ,
Where,
k = 0 or 1,
P0= 1st Reference Signal position and
P1 = 2nd Reference Signal position.
• So, an eNodeB with same frequency
shift cause interference.
PCI Planning PCI
8. Page 8
There are two main strategy options:
a) Neighboring sites are grouped into clusters, and each cluster is assigned a limited number of Code Groups.
• Each site is assigned to a specific Code Group and each sector a specific Color Group.
• PCIs should be split into 3 different color groups and 168 code groups.
• Code groups should be reserved for special purposes, e.g. in-building and PLMN borders or for future
expansions.
• If a color group is assigned per sector and a code group is assigned per site, this will eliminate the risk of
having the same k or frequency shift in the same site, in adjacent cells or pointing at each other.
b) Random planning , i.e. PCI plan that does not consider PCI grouping and does not follow any specific reuse
pattern
0 1 2 ...... 162 163 164 165 166 167
0 0 3 6 ...... 486 489 492 495 498 501
1 8 11 14 494 497 500 503 2 5
2 16 19 22 ...... 502 1 4 7 10 13
Alt. 1
Alt. 2
0 1 2 ...... 162 163 164 165 166 167
0 0 3 6 ...... 486 489 492 495 498 501
1 4 7 10 490 493 496 499 502 1
2 8 11 14 ...... 494 497 500 503 2 5
PCI Planning Schemes PCI
9. Page 9
0
12
Assign a color group
to each sector and a
code group per site
0
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k=0 Color group 0
k=1 Color group 1
k=2 Color group 237
40 39
0
120
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0
12
36
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43
• Typically 10-15 3-sector sites in a cluster.
• Use a subset of the code groups in each cluster.
• If there are ~70 code groups available, PCIs may be repeated every fifth or sixth cluster.
• Structured planning like this eliminates the risk of having conflicting k or frequency shift in the same site, in
adjacent cells or pointing at each other.
• Also the risk of having conflicting SSS sequences in adjacent cells is reduced – although this may appear at
cluster borders.
PCI Planning Schemes PCI
10. Page 10
The first strategy option is recommended to use in order to avoid non-optimal PCI combinations for adjacent
cells.
When planning PCIs the following priority orders are recommended:
• The same PCIs should be avoided within the same site and as neighbors.
• PCIs with conflicting k values should be avoided within the same site and as neighbors.
• PCIs with conflicting m0 and m1 values should be avoided within the same site and as neighbors.
Reasons for not following these rules strictly:
• Will not work in an irregular pattern (see previous slide).
• Will cause a lot of limitations on neighbors and neighbor lists have to be shortened.
PCI Planning Schemes PCI
11. Page 11
• PSS allocation defines the alignment of the CRS or data RE between neighbor cells.
• Depending on the scheme, more interference can occur on CRS or on data RE (PDCCH and/or PDSCH).
• Shifted Reference Signals: Using different PSSs in adjacent cells, the CRSs are allocated in different
subcarriers within a PRB.
• Non-Shifted Reference Signals: Using the same PSSs in adjacent cells, the CRSs are aligned and cause
collisions among the adjacent cells.
PCI Interference PCI
12. Page 12
• So, the levels of interference in the downlink, can be affected by the PSS plan / configuration, apart from
the propagation environment and the traffic distribution in time and space.
PCI Interference PCI
13. Page 13
• The allocation of physical layer cell identities is analogous to the scrambling code planning for UMTS.
• The isolation between cells which are assigned the same physical layer cell identity should be sufficiently
great to ensure that UE never simultaneously receive the same identity from more than a single cell.
• Specific physical layer cell identities can be excluded from the plan, to allow for future network expansion.
• Whenever possible, cells belonging to the same eNodeB should be allocated identities from within the
same group.
• In priority order, it should fulfilled:
- Avoid assigning the same PCI to neighbour cells.
- Avoid assigning the same mod3 (PCI) to ‘neighbour’ cells.
- Avoid assigning the same mod6(PCI) to ‘neighbour’ cells.
- Avoid assigning the same mod30 (PCI) to ‘neighbour’ cells.
Mod30 PCI to avoid UL-DM
RS interference in case
grpAssigPUSCH=0
Mod3 PCI to avoid
Reference Signal pollution
in case of n-ports antenna ,
where n>1
Id = 5
Id = 4
Id = 3
Id =
11
Id =
10
Id = 9
Id = 8
Id = 7
Id = 6
Id = 2
Id = 1
Id = 0
PCI Interference Mitigation PCI
14. Page 14
• In order to mitigate any issue with the PCI, some analysis / tools should be done:
• Run a prediction tool , like Atoll, Planet etc., with an updated database and propagation models. This
will provide a relative accurate indication of possible interference matrix. It will consider:
• Latitude/Longitude
• Azimuth
• RAD Center of the Site
• Electrical/Mechanical Tilts
• Antenna system configuration (model, Eirp etc.)
• PCI
• Band
• Propagation/Coverage Footprint of the Sector
• Clutter/Building data
• In networks with a non standard azimuths distribution, the graph next page may support strategies to
be applied. Approach:
• Identify sites that do not follow:
• PSS = 0 , sector alpha
• PSS = 1, sector beta
• PSS = 2, sector gamma
PCI Interference Mitigation PCI
15. Page 15
• Evaluate PCI of co PCI < 10 km after morphology, TA, SINR and HO measurements analysis (all
analysis tools are already available in ENIQ).
• Evaluate PSS MOD_3 of sites with distance smaller than 1 mi. Dense urban, metro, urban and
suburban.
• Propose changes and strategy according to clusters and site weight.
• The distribution in the graph shows that the sectors are oriented over a wide range of azimuths.
• The azimuth planning (design) followed CDMA existing network, which target coverage on expense
of standard azimuths.
PCI Interference Mitigation PCI
16. Page 16
• So based on this restriction, the best possible PCI retune cab be designed and implemented .
• Another approach is to correlate Sectors with low Sec Throughput (network measured) with the
results of the prediction toll or any other tool that presents a sort of interference penalties count.
• Vide example table below:
PCI Interference Mitigation PCI
Criteria for Low Speeds :
• For all sectors where DL Sec Speeds are less
than 80%, according to table above.
EARFCN / Priority Count of Priority Sum of Throughput < AVG Sum of Throughput < AVG2
8165 44 0 0
0 37 0 0
High 3 0 0
Low 1 0 0
Middle 3 0 0
8321 1716 12 12
0 1224 0 0
High 190 12 12
Low 81 0 0
Middle 221 0 0
8640 100 0 0
0 78 0 0
High 9 0 0
Low 3 0 0
Middle 10 0 0
8665 2369 40 40
0 1714 0 0
High 242 40 40
Low 112 0 0
Middle 301 0 0
8763 2260 126 126
0 1627 0 0
High 246 126 126
Low 107 0 0
Middle 280 0 0
Grand Total 6489 178 178
earfcndl (OSS) # Sectors DL Avg Sec Throughput MB/s 80%
8665 2369 8.27 6.61
8321 1716 7.22 5.77
8763 2260 5.76 4.60
8165 44 7.67 6.14
8640 100 10.69 8.55