The document provides guidelines for analyzing and troubleshooting exceptional reverse received signal strength indicator (RSSI) values in a CDMA network. It discusses various phenomena that can indicate RSSI issues, potential causes of exceptional RSSI including equipment problems, parameter settings, interference, and more. A flowchart is presented outlining steps for analyzing RSSI data, checking traffic statistics, alarms, historical operations, parameters, antennas/feeders, and interference to diagnose the root cause. Troubleshooting steps are also described for addressing issues found to be caused by interference.
Episode 25. Provide brief overview of DOCSIS CMTS best practices and optimization in regards to “new” commands & configurations. Recommendations and deviations from default settings are based on typical cable plant architectures & design. Recommendations may not apply in some scenarios. More detailed information about DOCSIS CMTS features should be obtained from your DOCSIS CMTS vendor. Topics listed in order as they appear when doing “show run” from Cisco cBR-8 CMTS
MeshDynamics MD4000 Training Webcast slidesMeshDynamics
MD4000 Node Deployment Training - Tutorial [30 min] Step by step instructions on configuring MeshDynamics MD4000 mesh nodes starting with power up, connecting to the network, antenna selection, node configuration options.
Episode 25. Provide brief overview of DOCSIS CMTS best practices and optimization in regards to “new” commands & configurations. Recommendations and deviations from default settings are based on typical cable plant architectures & design. Recommendations may not apply in some scenarios. More detailed information about DOCSIS CMTS features should be obtained from your DOCSIS CMTS vendor. Topics listed in order as they appear when doing “show run” from Cisco cBR-8 CMTS
MeshDynamics MD4000 Training Webcast slidesMeshDynamics
MD4000 Node Deployment Training - Tutorial [30 min] Step by step instructions on configuring MeshDynamics MD4000 mesh nodes starting with power up, connecting to the network, antenna selection, node configuration options.
FREQUENCY CONCEPTS
The following table summarizes the frequency-related specifications of each of the GSM systems. The terms used in the table are explained in the remainder of this section.
System P-GSM 900 E-GSM 900 GSM 1800
Frequencies: • Uplink • Downlink
890-915 MHz
935-960 MHz
Wavelength ~ 33 cm
880-915 MHz
925-960 MHz
GSM 1900
1710-1785 MHz
1805-1880 MHz
1850-1910 MHz
1930-1990 MHz
~ 33 cm ~ 17 cm ~ 16 cm
Bandwidth 25 MHz
35 MHz 75 MHz 60 MHz
Duplex Distance 45 MHz
45 MHz 95 MHz 80 MHz
Carrier Separation 200 kHz
1
Radio Channels
200 kHz 200 kHz 200 kHz
125
175 375 300
Transmission Rate 270 kbits/s
270 kbits/s 270 kbits/s 270 kbits/s
Table 3-1 Frequency-related specifications
FREQUENCY
F Did you know?
Due to frequency, a BTS transmitting information at 1800 MHz with an output power of 10 Watts (W) will cover only half the area of a similar BTS transmitting at 900 MHz. To counteract this, BTSs using 1800 MHz may use a higher output power.
An MS communicates with a BTS by transmitting or receiving radio waves, which consist of electromagnetic energy. The frequency of a radio wave is the number of times that the wave oscillates per second. Frequency is measured in Hertz (Hz), where 1 Hz indicates one oscillation per second. Radio frequencies are used for many applications in the world today. Some common uses include:
• Television: 300 MHz approx. • FM Radio: 100 MHz approx. • Police radios: Country dependent • Mobile networks: 300 - 2000 MHz approx.
The frequencies used by mobile networks varies according to the standard being used
2
. An operator applies for the available frequencies or, as in the United States, the operator bids for frequency bands at an auction. The following diagram displays the frequencies used by the major mobile standards:
DAMPS 1900 MHz
0450900800 1500 1800 1900 NMT 450
PDC 800
GSM 900 GSM 1800 GSM 1900NMT 900
PDC 1500AMPS DAMPS 800
TACS
Figure 3-1 Frequencies for major mobile standards
Neighboring Wi-Fi networks, RF noise sources, and indoor and outdoor coverage patterns can all impact mobile device performance on WLANs. This session will give you a better understanding of radio coverage patterns for different types of antennas and covers related essentials in the Wi-Fi standard. Join us also to learn more about 802.11ac, multi-user MIMO and transmit beamforming with Wave 2, and more.
Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s
Half rate => Used for speech at 6.5 Kbits/s
or sending data at 4.8 Kbits/s
Enhanced Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s but
with almost Land line quality
FCCH = FREQUENCY CORRECTION CHANNEL
=> To tell the Mobile that this is the BCCH carrier
=> To able the Mobile to synchronize to the frequency
(Downlink only)
SCH = SYNCHRONISATION CHANNEL
=> Used for sending BSIC (Base station Identity Code)
=> Give TDMA frame number to the Mobile.
(Downlink only)
BCCH = BROADCAST CONTROL CHANNEL
=> Used for sending information to the mobile like
CGI (Cell Global identity), LAI (Location Area Identity),
BCCH carriers of the neighboring cells,
maximum output power allowed in the cell and other
broadcast messages like barred cell. (Downlink only)
PCH = PAGING CHANNEL
=> Used for paging the Mobile. (Downlink only)
Reason could be an incoming call or an incoming Short Message.
RACH = RANDOM ACCESS CHANNEL
=> Used for responding to the paging (terminating), Location updating
or to make call access (originating) by asking for a signaling channel.
(Uplink only)
AGCH = ACCESS GRANT CHANNEL
=> Used to allocate SDCCH to the mobile.
(Downlink only)
Spectrum management best practices in a Gigabit wireless worldCisco Canada
With the introduction of 802.11ac the news is full of the potential for Gigabit networking. Very few of us will have the luxury of running a network that strictly supports 802.11ac and that means a mixed environment for most of us. Get the facts on what 802.11ac means to you, how to evaluate using 20, 40, 80 or 160 Mhz OBSS/Channels. How does RRM's DCA handle a mixed environment and what performance considerations do you need to consider to make decisions that make the best of the spectrum you have today and in the future. What is in the future for our spectrum? To learn more please visit our website here: http://www.cisco.com/ca/
The global coverage of the 2.4 GHz ISM band has ensured its visibility among device vendors. In addition to the rapid increase of devices to be deployed, the number of RF technologies and protocols sharing this band has also increased.
Of course, it is important that all devices operate well and within the regulation of the band, but even then, the chances of RF interference between devices in the band are considerable (see Figure 1).
This interference can lead to packet loss, increased power consumption, and degraded network performance. The key to maintaining good coexistence with other devices in the band is robustness in terms of interference.
A frequency shortcut scheme and good selectivity for this application can ensure that this coexistence is achieved.
Discussing the Industrial Internet and the crucial role that low-power wireless sensor networks will play to gather these vast amounts of data. Describing how existing industrial wireless technologies must be extended to reach higher scales at lower costs (albeit, with lower guarantees), and the architectural approach and standards that are being developed at 6TiSCH, which encompasses work at IETF, IEEE, and industrial standard bodies.
FREQUENCY CONCEPTS
The following table summarizes the frequency-related specifications of each of the GSM systems. The terms used in the table are explained in the remainder of this section.
System P-GSM 900 E-GSM 900 GSM 1800
Frequencies: • Uplink • Downlink
890-915 MHz
935-960 MHz
Wavelength ~ 33 cm
880-915 MHz
925-960 MHz
GSM 1900
1710-1785 MHz
1805-1880 MHz
1850-1910 MHz
1930-1990 MHz
~ 33 cm ~ 17 cm ~ 16 cm
Bandwidth 25 MHz
35 MHz 75 MHz 60 MHz
Duplex Distance 45 MHz
45 MHz 95 MHz 80 MHz
Carrier Separation 200 kHz
1
Radio Channels
200 kHz 200 kHz 200 kHz
125
175 375 300
Transmission Rate 270 kbits/s
270 kbits/s 270 kbits/s 270 kbits/s
Table 3-1 Frequency-related specifications
FREQUENCY
F Did you know?
Due to frequency, a BTS transmitting information at 1800 MHz with an output power of 10 Watts (W) will cover only half the area of a similar BTS transmitting at 900 MHz. To counteract this, BTSs using 1800 MHz may use a higher output power.
An MS communicates with a BTS by transmitting or receiving radio waves, which consist of electromagnetic energy. The frequency of a radio wave is the number of times that the wave oscillates per second. Frequency is measured in Hertz (Hz), where 1 Hz indicates one oscillation per second. Radio frequencies are used for many applications in the world today. Some common uses include:
• Television: 300 MHz approx. • FM Radio: 100 MHz approx. • Police radios: Country dependent • Mobile networks: 300 - 2000 MHz approx.
The frequencies used by mobile networks varies according to the standard being used
2
. An operator applies for the available frequencies or, as in the United States, the operator bids for frequency bands at an auction. The following diagram displays the frequencies used by the major mobile standards:
DAMPS 1900 MHz
0450900800 1500 1800 1900 NMT 450
PDC 800
GSM 900 GSM 1800 GSM 1900NMT 900
PDC 1500AMPS DAMPS 800
TACS
Figure 3-1 Frequencies for major mobile standards
Neighboring Wi-Fi networks, RF noise sources, and indoor and outdoor coverage patterns can all impact mobile device performance on WLANs. This session will give you a better understanding of radio coverage patterns for different types of antennas and covers related essentials in the Wi-Fi standard. Join us also to learn more about 802.11ac, multi-user MIMO and transmit beamforming with Wave 2, and more.
Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s
Half rate => Used for speech at 6.5 Kbits/s
or sending data at 4.8 Kbits/s
Enhanced Full rate => Used for speech at 13 Kbits/s
or sending data at 9.6 Kbits/s but
with almost Land line quality
FCCH = FREQUENCY CORRECTION CHANNEL
=> To tell the Mobile that this is the BCCH carrier
=> To able the Mobile to synchronize to the frequency
(Downlink only)
SCH = SYNCHRONISATION CHANNEL
=> Used for sending BSIC (Base station Identity Code)
=> Give TDMA frame number to the Mobile.
(Downlink only)
BCCH = BROADCAST CONTROL CHANNEL
=> Used for sending information to the mobile like
CGI (Cell Global identity), LAI (Location Area Identity),
BCCH carriers of the neighboring cells,
maximum output power allowed in the cell and other
broadcast messages like barred cell. (Downlink only)
PCH = PAGING CHANNEL
=> Used for paging the Mobile. (Downlink only)
Reason could be an incoming call or an incoming Short Message.
RACH = RANDOM ACCESS CHANNEL
=> Used for responding to the paging (terminating), Location updating
or to make call access (originating) by asking for a signaling channel.
(Uplink only)
AGCH = ACCESS GRANT CHANNEL
=> Used to allocate SDCCH to the mobile.
(Downlink only)
Spectrum management best practices in a Gigabit wireless worldCisco Canada
With the introduction of 802.11ac the news is full of the potential for Gigabit networking. Very few of us will have the luxury of running a network that strictly supports 802.11ac and that means a mixed environment for most of us. Get the facts on what 802.11ac means to you, how to evaluate using 20, 40, 80 or 160 Mhz OBSS/Channels. How does RRM's DCA handle a mixed environment and what performance considerations do you need to consider to make decisions that make the best of the spectrum you have today and in the future. What is in the future for our spectrum? To learn more please visit our website here: http://www.cisco.com/ca/
The global coverage of the 2.4 GHz ISM band has ensured its visibility among device vendors. In addition to the rapid increase of devices to be deployed, the number of RF technologies and protocols sharing this band has also increased.
Of course, it is important that all devices operate well and within the regulation of the band, but even then, the chances of RF interference between devices in the band are considerable (see Figure 1).
This interference can lead to packet loss, increased power consumption, and degraded network performance. The key to maintaining good coexistence with other devices in the band is robustness in terms of interference.
A frequency shortcut scheme and good selectivity for this application can ensure that this coexistence is achieved.
Discussing the Industrial Internet and the crucial role that low-power wireless sensor networks will play to gather these vast amounts of data. Describing how existing industrial wireless technologies must be extended to reach higher scales at lower costs (albeit, with lower guarantees), and the architectural approach and standards that are being developed at 6TiSCH, which encompasses work at IETF, IEEE, and industrial standard bodies.
The IEEE 802 is a family of IEEE standards dealing with Local Area Networks and Metropolitan Area Networks. The IEEE 802 family of standards is maintained by the IEEE 802 LAN/MAN Standards Committee (LMSC).
The most widely used standards are for the Bridging and Virtual Bridged LANs (802.1), Ethernet family (802.3), Token Ring (802.5) and Wireless LAN (802.11).
Basic Telecom concepts
Various Wireless Technologies
Cellular concepts & Principal of cellular Comm.
GSM Network Architecture
GSM channel Architecture
Call Flows in GSM
GSM Planning steps (Nominal Plan & RF surveys)
Alternative means of wireless communication
Walkie - Talkie
Pagers
Trunked private radios
Mobile Phone - the magic technology that enables everyone to communicate anywhere with anybody.
Till 1982 Cellular Systems were exclusively Analog Radio Technology.
Advanced Mobile Phone Service (AMPS)
U.S. standard on the 800 MHz Band
Total Access Communication System (TACS)
U.K. standard on 900 MHz band
Nordic Mobile Telephone System (NMT)
Scandinavian standard on the 450 & 900 MHz band
The GSM standard was developed by the Groupe SpecialMobile, which was an initiative of the Conference of European Post and Telecommunications (CEPT) administrations.
The responsibility for GSM standardization now resides with the
Special Mobile Group (SMG) under the European Telecommunication Standard Institute (ETSI).
Fully digital system utilizing the 900MHz frequency band.
TDMA over radiocarriers(200 kHz carrier spacing)
8 full rate or 16 half rate TDMA channels per carrier
User/terminal authentication for fraud control
Encryption of speech and data transmissions over the radio path
Full international roaming capability
Low speed data services (upto 9.6kb/s)
Compatibility with ISDN for supplementary services
Support of short message services(SMS)
GSM supports a range of basic and supplementary services, and these services are defined analogous to those for ISDN(i.e.,bearer services, teleservices, and supplementary services).
The most important service supported by GSM is Telephony.
Other services derived from telephony included in the GSM specification are emergency calling and voice messaging.
Bearer services supported in GSM include various asynchronous and synchronous data services for information transfer.
Teleservices based on these bearer services include group 3 fax and short message service(SMS)
The data capabilities of GSM have now been enhanced to include high speed circiut-switched data(HSCSD) and general packet radio service (GPRS).
Call offering services call forwarding
Call resrtiction services call barring
Call waiting service
Call hold service
Multi party service tele conferencing
Calling line presentation restriction services
Advice of charge service
Closed user group service
The GSM System comprises of Base Transceiver Station (BTS), Base Station Controllers (BSC), Mobile Switching Centers (MSC), and set of registers (databases) to assist in mobility management and security functions.
All signaling between the MSC and the various registers (databases) as well as between the MSCs takes place using the Signaling System 7(SS7) network, with the application level messages using the Mobile Application Protocol (MAP) designed specifically for GSM.
The MAP protocol utilizes the lower layer functions from the SS7 protocol stack.
ell Allocation (CA) is the subset of the total frequency band that is available for one BTS. It can be viewed as the total transport resource available for traffic between the BTS and its attached MSs. One Radio Frequency CHannel (RFCH) of the CA is used to carry synchronization information and the Broadcast Control CHannel (BCCH). This can be any of the carriers in the cell and it is known as the BCCH carrier or the c
carrier. Strong efficiency and quality requirements have resulted in a
0
rather complex way of utilizing the frequency resource. This chapter describes the basic principles of how to use this resource from the physical resource itself to the information transport service offered by the BTS.
Carrier separation is 200 kHz, which provides: • 124 pairs of carriers in the GSM 900 band • 374 pairs of carriers in the GSM 1800 band • 299 pairs of carriers in the GSM 1900 band
Using Time Division Multiple Access (TDMA) each of these carriers is divided into eight Time Slots (TS). One TS on a TDMA frame is called a physical channel, i.e. on each duplex pair of carriers there are eight physical channels.
A variety of information is transmitted between the BTS and thMS. The information is grouped into different logical channelsEach logical channel is used for a specific purpose such as paging, call set-up and speech. For example, speech is sent on the logical channel Traffic CHannel (TCH). The logical channels are mapped onto the physical channels.
The information in this chapter does not include channels specific for GPRS (General Packet Radio Service). For basic information on GPRS see chapter 14 of this documentation.
Common core mechanics in Nokia UltraSite EDGE BTS Outdoor and Nokia UltraSite EDGE BTS Indoor
Common plug-in units
1940 x 770 x 750 mm (H x W x D)
Identical footprint to CityTalk BTS
Weight
Max weight (12 TRX) 340 kg
Heaviest single part 58 kg (core mechanics)
Heaviest plug-in unit 18 kg (RTC)
Acoustic noise (max): 68 dB(A)
Climatic conditions:
w/o heater -10°C ... +50°C
with optional heater -33°C ... +50°C
Ingress Protection Class: IP 55
Two level environmental protection:
BTS core and cabinet door provides EMC shielding
Outdoor kit provides additional weather proofing
The GENEX Assistant is excellent software tool for
Post-Processing 2G & 3G Drive Test Data.
With the GENEXAssistant, you can:
Have a panorama view of network performance
Locate network troubles
Improve network quality
Verify network planning and optimization
ANALYSIS OF LOGFILE
FOR POST PROCESSING OF LOGFILE IN
GENEX ASSISTANCE WE NEED TO
OPEN A NEW PROJECT
. Overview
2. Handover Causes & Priorities
3. Threshold Comparison Process
4. Target Cell Evaluation Process
5. Handover Algorithms
Power Budget (PBGT)
Level & Quality (RXLEV & RXQUAL)
Umbrella (& Combined Umbrella/PBGT)
MS Speed (FMMS & MS_SPEED_DETECTION)
6. Imperative Handovers
Distance
Rapid Field Drop (RFD) & Enhanced Rapid Field Drop (ERFD)
7. Handover Timers
Call continuity - to ensure a call can be maintained as a MS moves geographical location from the coverage area of one cell to another
Call quality - to ensure that if an MS moves into a poor quality/coverage area the call can be moved from the serving cell to a neighbouring cell (with better quality) without dropping the call
Traffic Reasons - to ensure that the traffic within the network is optimally
distributed between the different layers/bands of a network
If 2 or more handover (PC) criteria are satisfied simultaneously the following priority list
is used in determining which process is performed;
. Uplink and downlink Interference
2. Uplink quality
3. Downlink quality
4. Uplink level
5. Downlink level
6. Distance
7. Enhanced (RFD)
8. Rapid Field Drop (RFD)
9. Slow moving MS
10. Better cell i.e. Periodic check (Power Budget HO or Umbrella HO)
11. PC: Lower quality/level thresholds (UL/DL)
12. PC: Upper quality/level thresholds (UL/DL)
Introduction
Channel Configuration
Idle Mode Operation
Protocols
Radio resources
Measurements
Power Control
HO process
Intelligent Underlay Overlay
Handover Support for Coverage Enhanchements
The extended cell
Dynamic Hotspot
Dual band GSM/DCS Network Operation
Half Rate
HSCSD
Transmission management in BSS is a feature used in managing the Base Station Subsystem transmission system functions such as supervision, alarms, statistics
and settings. The network element mainly responsible for transmission management in BSS is the Base Station Controller (BSC).
Transmission management functionalities make it possible for the operators to manage the transmission equipment remotely from the BSC or from Nokia
NetAct integrated network management system, which simplifies network maintenance and operation. Supervision functions help minimise the time spent in maintenance, and statistics collection helps the operators analyse and optimise
the use of their transmission equipment. Moreover, new software can be downloaded in a way that does not interfere with the traffic.
Hardware and software requirements BSS transmission network elements
BSS transmission management functionalities Transmission parameters Transmission alarms
Transmission measurements
2.Hardware and software requirements
There are no specific hardware or software requirements for the transmission management functionalities. However, the type of the BTS poses certain
limitations.
The BTS type specific functionalities are listed in the table below.
More details about the functionalities can be found in BSS transmission management functionalities .
Polling list sending with priority is a functionality used in positioning. To ensure accurate positioning calculations, the LMU unit must supply Radio Interface Timing System (RIT) information to the network faster than the normal Q1 polling is able to do. Faster LMU polling is achieved by defining a Q1 polling
priority for each Q1 device, with the LMU having the highest priority. For more information see Location Services .
3.BSS transmission network elements
The base Station Subsystem (BSS) consists of at least one Base Station Controller (BSC) and its Base Transceiver Stations (BTS). The Transcoder Submultiplexer
(TCSM) is also part of the BSS although it is actually located in the MSC site. The three basic configurations (topologies) for transmission between the BSC and
the BTSs are: point-to-point connection
multidrop chain multidrop loop
In point-to-point configuration each BTS is connected directly to the BSC. In the multidrop chain, BTSs form a chain and the first BTS in the network is connected directly to the BSC. In the loop connection, the BTSs form a loop where the first and the last BTS in the loop are connected directly to the BSC via a crossconnecting node. The topology used depends on a number of factors such as the distance between the BSC and the BTS, the number of transceivers (TRXs) used at a particular BTS site and the signalling channel rate between the BSC and the\ BTS. Usually the topology used is a mixture of the three basic topologies. Formore information on the topologies, refer to Nokia BSS Transmission\Configuration .
– There are others : IS95 HDR, EDGE, etc.
» Direct Spread CDMA TDD
» Direct Spread CDMA FDD
» Multi-carrier CDMA FDD
Global 3G comprises of 3 modes :
– Marketed as Global 3G CDMA implying a single unified standard. In reality,
– Mostly dominated by Direct Sequence CDMA.
– Market is expected to be fragmented amongst several competing
IMT2000 guidelines defined by the ITU.
– Analog was 1G. GSM/IS95 were 2G. Next is 3G.
What is 3G ?
standards.
across the world.
Envisioned as a single Global standard allowing seamless roaming
Used interchangeably with IMT2000 although there are some specific
A loosely defined term referring to next generation wireless systems.
4
encompasses three optional modes of operation.”
Telecommunications Union (ITU) of a single CDMA third generation standard that
“Qualcomm and Ericsson ... jointly support approval by the International
Jun 1999 found compromise at the OHG.
“Qualcomm … is not prepared to grant licences according to the … ETSI IPR Policy.”
fair, reasonable and non-discriminatory basis in accordance with the ... ETSI IPR Policy.”
“Ericsson … is prepared to grant licences to these [W-CDMA & TD-CDMA] patents on
Dec 1998 saw a stand-off in standards.
WCDMA, WTDMA, OFDMA, Global CDMA 1 & 2.
Asia Pacific (ARIB & TTA):
WCDMA N/A, UWC-136, cdma2000, WIMS WCDMA, WP-CDMA.
North America(T1P1, TR45.3, TR45.5, TR46.1):
WCDMA, WTDMA,TDMA/CDMA, OFDMA, ODMA.
Europe (ETSI):
In
n
scrambling achieve?
scrambling achieve?
6
Secure link: a linear sequence of length 2
doesn’t
Benefits of wideband signals: multipath provides temporal diversity instead of ISI.
Spectral re-use factor of 1: all cells can use the same frequency spectrum.
does
What
What
Low cross-correlation (at any time offset).
High auto-correlation (at any time offset).
What are their important properties?
in to a low amplitude, wide bandwidth signal.
Converts a high amplitude, narrow bandwidth signal
How do they work?
Pseudo-random sequences: Gold codes, Kasami codes (M-sequences).
‘W’ of WCDMA.
W
Cdma2000 network problem analysis with mobile station 20030212-a-v1.0Tempus Telcosys
Keyword: CDMA, forward coverage, reverse coverage and connection
Abstract: This document describes how to use a Mobile Station (MS) to locate network problems. That is, judge the forward/reverse coverage by viewing the indices displayed on the Debug screen of MS. Then locate the network problems according to reverse Frame Error Rate (FER) and Received Signal Strength Indicator (RSSI) test on the background. This document uses H100 MS as an example for the description. For settings of other CDMA MSs, see the relevant document.
1.1
Displaying Debug Screen of H100 MS
1.2
1) 2) 3) 4)
Switch on the MS; Input password: ##27732726; Press the red Power-off key; Select 3.
The Debug screen is displayed.
Index Value on Debug Screen
Assume that the following information is displayed on the Debug screen:
P232 R085 C0210
03612-00001-1
PAGE Ec: -5.0
RX: -75 TX: NoTx
P232: PN of primary service sector
C0210: System operating frequency
03612: SID
00001: NID
PAGE: Channel mode
Ec: Ec/Io
Rx: Receive level of MS
TX: Transmit level of MS
Thou
It is required that after the course study
you should:
Have a general concept about DT
Master Panorama DT operation
Master Panorama data analysis
Chapter 1 DT Introduction
Chapter 2 Panorama DT Introduction
Chapter 3 Panorama DT Data Analysis
Collect System Air interface data
Analyze Air interface data
Assist Export Analysis report
Qualcom CAIT
CDMA Air Interface Tester
WILL TECH DM2K/Pecker
Pecker Navigator, Pecker Analyzer
Panorama
Qualcom CAIT
CDMA Air Interface Tester
WILL TECH DM2K/Pecker
Pecker Navigator, Pecker Analyzer
Panorama
QCTest™ CDMA Air Interface Tester (CAIT™) 3.1 User’s GuideTempus Telcosys
QUALCOMM Proprietary
Export of this technology or software is regulated by the U.S. Government. Diversion contrary to Ulaw prohibited.
All data and information contained in or disclosed by this document are confidential and proprietinformation of QUALCOMM Incorporated, and all rights therein are expressly reserved. By acceptthis material, the recipient agrees that this material and the information contained therein are heldconfidence and in trust and will not be used, copied, reproduced in whole or in part, nor its contentsrevealed in any manner to others without the express written permission of QUALCOMM Incorporated.
Mobile communications is one of the communications fields that develop rapidly and energetically. The antenna builds the bridge between user terminals and base control devices. It is widely used in the mobile communications and the wireless access communication system. The rapid development of the antenna greatly promotes its technology innovation.
It is important to deeply grasp the knowledge of the antenna, which is useful to:
Install and maintain products.
Promote the network planning.
Chapter 1 Working Principle
Chapter 2 Classification
Chapter 3 Electrical Index
Chapter 4 Mechanical Index
When the conducting cable carries the alternating current, the electromagnetic wave radiation can be formed.
If two conducting cables are close, the directions of their current are opposite, and the electromotive force is counteracted. Thus the radiation becomes week.
If two conducting cables are open, the directions of their current are the same. Thus the radiation becomes strong.
When the length of the conducting cable is like the wavelength, the current on the cable will be enhanced. Thus the radiation becomes strong.
The straight conducting cable which can generate the strong radiation is called the dipole.
The pole whose two arms are of the same length (1/4 Wavelength) is called as dipole or half-wave-length dipole.
C cf radio propagation theory and propagation modelsTempus Telcosys
The radio propagation theory is an important lesson in the radio communication curriculum. This lesson answers the following questions:
How are radio waves transmitted from one antenna to the other antenna?
What features does the radio wave have during the propagation? Which factors affect the propagation distance?
What fruits are achieved by predecessors in the radio wave propagation theory? How to apply the theory to practice?
Chapter 1 Radio Propagation Theory
Chapter 2 Radio Propagation Environment
Chapter 3 Radio Propagation Models
What is Handoff in mobile network?
What is the Search Window?
How to optimize handoff parameters?
Upon completion of this course, you will be able to:
Know handoff principle and classification.
Know search window and key parameters.
Master handoff tuning in network.
Chapter 1 Basic Concept
Chapter 2 Handoff in CDMA
Chapter 3 Optimization Command
Chapter 4 Summary
Soft handoff
It is a process of establishing a link with a target sector before breaking the link with the serving sector.
Softer handoff
Similar to the soft handoff, but the softer handoff is occurred among multi-sectors in the same base station.
Hard handoff
Hard handoff occurs when the two sectors are not synchronized or are not on the same frequency. Interruption in voice or data communication occurs but this interruption does not effect the user communication.
CDMA soft handoff is driven by the handset
Handset continuously checks available pilots
Handset tells system pilots it currently sees
System assigns sectors (up to 6 max.), tells handset
Handset assigns its fingers accordingly
All messages sent by dim-and-burst, no muting!
Each end of the link chooses what works best, on a frame-by-frame basis!
Users are totally unaware of handoff
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
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CDMA System RSSI Exceptional
1. Document
number
Product name CDMA
Used by Huawei engineers Product version
Drafted by CDMA RNP Document version 1.0
CDMA System RSSI Exceptional
Troubleshooting Guideline V1.0
Prepared by Si Binhe (54736) Date March 2007
Reviewed by Date
Approved by Date
Tempus Telcosys (P).,Ltd.
Time is Almighty
www.TempusTelcosys.com
2. Contents
1 Overview..................................................................................................................3
2 RSSI Exceptional Analysis...................................................................................4
2.1 RSSI Exceptional Phenomena......................................................................................................4
2.1.1 Subscriber Experience.............................................................................................................4
2.1.2 Terminal Phenomena...............................................................................................................4
2.1.3 Traffic Statistics OMC Phenomena .......................................................................................4
2.1.4 Other Phenomena....................................................................................................................4
2.2 RSSI Exceptional Classifications..................................................................................................5
2.2.1 RSSI Exceptional Caused by Poor Engineering Quality........................................................5
2.2.2 RSSI Exceptional Caused by Parameter Settings...................................................................5
2.2.3 RSSI Exceptional Caused by Equipment Abnormality...........................................................5
2.2.4 RSSI Exceptional Caused by Unallocated Terminals.............................................................6
2.2.5 RSSI Exceptional Caused by Base Station Blocking..............................................................6
2.2.6 RSSI Exceptional Caused by Heavy Traffic...........................................................................6
2.2.7 RSSI Exceptional Caused by External Interference...............................................................6
2.2.8 Summary of RSSI Exceptional and Relevant Causes.............................................................8
2.3 RSSI Exceptional Analysis Steps..................................................................................................9
2.3.2 Traffic Statistics Analysis......................................................................................................11
2.3.3 Alarm Data Analysis.............................................................................................................12
2.3.4 Historical Operations Analysis.............................................................................................12
2.3.5 Parameter Checking.............................................................................................................13
2.3.6 Antenna and Feeder Checking..............................................................................................14
2.3.7 Interference Testing...............................................................................................................14
2.3.8 Summary and Conclusions....................................................................................................15
3 RSSI Exceptional Troubleshooting...................................................................16
3.1 Interference Testing.....................................................................................................................16
3.2 Interference Data Analysis..........................................................................................................16
3.3 Determining Interference Troubleshooting Solution..................................................................17
3.4 Eliminating Interference.............................................................................................................17
3.5 Verification..................................................................................................................................17
www.TempusTelcosys.co
3. 1 Overview
Reverse received signal strength indicator (RSSI) is the reverse signal
reception indicator in 1.2288 MHz band of base station. Normal RSSI
indicates that the reverse channel is operational.
In actual networks, RSSI exceptional may be contributed to
engineering quality, equipment, terminal, parameter settings, and
interference. That is, RSSI exceptional does not means the
interference exists in the network.
www.TempusTelcosys.com
4. 2 RSSI Exceptional Analysis
2.1 RSSI Exceptional Phenomena
2.1.1 Subscriber Experience
User average access time is larger than 5 seconds.
In serious conditions, the subscribers are hard to access the
system.
Audio discontinuity, noise, silence, monologue call or even call
drop exists during a call.
2.1.2 Terminal Phenomena
Terminal transmit power is very high, Rx + Tx > -70dBm.
The terminal cannot access the system for a long period of time.
20 seconds later, the terminal is dropped from the network and
researches a network.
2.1.3 Traffic Statistics OMC Phenomena
RSSI of carrier with slow access speed is larger than-95dBm.
RSSI of carrier that access unavailable is larger than -80dBm.
RSSI is too small, and is smaller than -120dBm for a long period
of time.
The difference between main RSSI and diversity RSSI exceeds
6dB for a long period of time.
2.1.4 Other Phenomena
In the RFMT data tracing, the indicators, such as RevBadFrame,
RevSetEbNt, FwdFer, FwdSetEbNt, and MsRxPwr are degraded.
www.TempusTelcosys
5. 2.2 RSSI Exceptional Classifications
2.2.1 RSSI Exceptional Caused by Poor Engineering
Quality
RSSI exceptional is caused by base station equipment, for example,
the improper installation, connectors loosen, antenna soaked, or
antenna aging. In such cases, the difference between main RSSI and
diversity RSSI is large or RSSI is too small.
2.2.2 RSSI Exceptional Caused by Parameter Settings
Initial access power parameter is set to a large value.
TCH minimum gain is too large.
LAC division error, Reg_zone boundary zone, Total_zone, and
Zone_timer settings are improper or Reg_zone setting is incorrect,
resulting in frequency registrations of terminals. In such cases, the
RSSI may be increased.
Open access macro diversity (partial exceptional terminals).
Layer 2 acknowledgment of base station is not enabled (mainly for
IS95 MSs).
In such cases, main RSSI and diversity RSSI are high simultaneously.
2.2.3 RSSI Exceptional Caused by Equipment
Abnormality
RSSI exceptional caused by equipment abnormality has two types:
RSSI exceptional is caused by RF front end. The RF front end
problems contain passive intermodulation due to antenna
damaged. The power capacity limit is insufficient, and the RSSI is
worse after the multi-carrier is enabled. RSSI exceptional also can
be caused by the connector intermodulation, or lightning arrester
abnormality.
RSSI exceptional is caused by BAM abnormality, for example,
transmission or BSC resource allocation module failure, and many
calls are rejected frequently, result in the repeated calls. There are
too many network busy hour attempts, for example, over 3000
attempts. The traffic statistics or CSL shows that many calls are
released abnormally.
In such cases, main RSSI and diversity RSSI are high simultaneously.
www.TempusTelcosys
6. 2.2.4 RSSI Exceptional Caused by Unallocated
Terminals
When some MSs and FWTs whose techniques are inconsistent with
the CDMA industry standards access the network, the terminals
neglect the power control messages delivered by the network, or the
power control commands delivered by the system are invalid for the
terminals.
In actual networks, the unallocated MSs or FWTs whose techniques
are inconsistent with industry specifications increase the noise floor of
network.
In such cases, main RSSI and diversity RSSI are high simultaneously.
2.2.5 RSSI Exceptional Caused by Base Station
Blocking
When the base station is blocked or the baseband gain is set to a
small value, the base station becomes a receiver. The MSs within its
coverage range cannot receive the signals of this site, and access the
surrounding base stations for launching services.
The MSs near the site are far away from surrounding base stations.
When the MSs access the surrounding base stations for launching
services, large transmit power is required to ensure the communication
with surrounding base stations. The RSSI of this site is affected
dramatically.
In such cases, main RSSI and diversity RSSI are high simultaneously.
2.2.6 RSSI Exceptional Caused by Heavy Traffic
When the RSSI is too high or the difference between main RSSI and
diversity RSSI is large, check the traffic of this carrier first.
If the traffic is heavy (>30Erl) and RSSI is changed with the traffic, the
RSSI exceptional may be caused by the heavy traffic. We exploit the
potentials of existing network or consider network expansion to reduce
the carrier load and realize the load sharing. When the traffic is
reduced, RSSI is restored to a normal value.
In such cases, main RSSI and diversity RSSI are high simultaneously.
2.2.7 RSSI Exceptional Caused by External
Interference
Interphone interference
The interphone interference is mainly present in the hotels, office
www.TempusTelcosys
7. buildings, and governmental organizations. The interference of
interphone system is generated at random.
Generally, it is used almost 24 hours one day. Therefore, the
interference is hard to control. The interphone transmits small power
and the interference range is small, so the adjacent channel
interference and intermodulation interference have small impact.
This kind of interference can be avoided if the frequency band used by
the interphone system is far away from the frequency band we use.
Repeater interference
At the early stage of network construction, the repeater was used to
extend the coverage range of base station. It increases the noise floor
of CDMA system.
If the use of repeater in the network is inappropriate, the interference
to the base station is generated easily, affecting the CDMA coverage
range and reducing the quality of service.
The following types of repeater interference are available:
(1) RSSI is increased because of large reverse gain.
(2) The components of repeater are invalid.
(3) The repeater installation is not standardized, and insufficient
isolation exists between donor antenna and user antenna and the self-
excitation is generated, affecting the normal operation of base station
that the repeater is attached.
Self-excitation
After the signals transmitted from the repeater are received again
through the donor antenna, the signals are amplified through the
repeater and then are transmitted. The amplified signals are received
and then amplified. Such circle results in a bad condition.
Radar station and TV station interference
The frequency used by Some decimetric wave radars designed in
1970’ and 1980’ is similar to 800MHz frequency of CDMA system.
The transmit power is large, so the power level reaches several tens to
hundreds kw range and the outband spurious emission is large, easily
interfering to the adjacent 800MHz base stations.
The TV station mainly operates at 450 MHz frequency band, and
easily interferes to 450MHz CDMA system.
www.TempusTelcosys
8. AMPS interference without frequency retire
The original military AMPS system operates at the same frequency
band with CDMA2000 1X.
If the frequency band used by original military AMPS system was not
retired and is still used in some regions, it interferes to CDMA20001x
system operating at 800MHz frequency band.
Microwave transmission interference
The transmission microwave transmission links exist in many places.
These microwave transmissions operate at a high frequency band
(about 2 GHz). They have a small impact on existing 800MHz CDMA
network but interfere to the network operating at about 2000 MHz,
such as CDMA 1900MHz.
Other interference
The types of communication devices are various. Some companies
use the frequency band inconsistent with the industry standard and
occupy the frequency band for CDMA 1x being constructed.
The placement and isolation are inappropriate, so many dedicated
communication devices interfere to the coverage areas of CDMA
network.
In addition, there are broadband noises generated by the electric arc
and sparkles of electricity factor and electricity station.
Other types of interference sources are available, such as conference
interference system, computer screen interference unit, neon light
strike, TV active receiver, and high voltage transformer.
In such cases, the main RSSI and diversity RSSI are increased
simultaneously or the unipolarization RSSI is high.
2.2.8 Summary of RSSI Exceptional and Relevant
Causes
RSSI Exceptional Phenomenon Possible Causes
RSSI too low Main/diversity RSSI is smaller
than -110dBm for a long period of
time.
The connectors of antenna
and feeder are connected
insecurely or antenna and
feeder, TRX, CDU, or power
amplifier are faulty.
RSSI too high Main/diversity RSSI is higher than
-95dBm for a long period of time
or within a certain period of time.
Switch and jumper errors,
hardware faulty, water
penetrated in connectors,
www.TempusTelcosys
9. antenna and feeder standing
wave, parameter settings
(registration and access
message settings
inappropriate), system faulty,
spurious emission and
intermodulation, and external
interference
RSSI main and
diversity difference
large
The difference between main
RSSI and diversity RSSI is over
6dB or RSSI main/diversity
comparison alarm and TRM
main/diversity reception alarm
exist.
Antenna and feeder standing
wave, antenna installation
problems, hardware faulty,
diversity bypass switch setting
error, and external
interference
2.3 RSSI Exceptional Analysis Steps
The analysis of reverse RSSI is showed in Figure 1.1.
Analyze the RSSI data collected first.
If main/diversity RSSI is higher than -95dBm for a long period of time
or within a certain period of time, or The difference between main RSSI
and diversity RSSI is over 6dB, it may be caused by the heavy traffic,
equipment fault, manual operation, or external interference.
In such cases, collect the RSSI data within a week and check the
change of RSSI within this period of time. According to the information,
as well as alarms and historical operations, determine roughly the
causes of RSSI exception, and identify the causes according to the
following flowchart to tackle the RSSI exceptional problem.
www.TempusTelcosys
11. Figure 1.1 Flowchart of RSSI exceptional analysis
2.3.2 Traffic Statistics Analysis
Heavy traffic
When finding that the RSSI is too high or the difference between main
RSSI and diversity RSSI is large, check the traffic of carrier first. If the
traffic is high (> 30Erl) and RSSI is changed with the traffic, the RSSI
exceptional may be caused by heavy traffic.
We exploit the potentials of existing network or consider network
expansion to reduce the carrier load and realize the load sharing.
When the traffic is reduced, check whether RSSI is restored to a
normal value.
ACH occupation and call attempts analysis
Check the ACH occupation.
If the ACH occupation exceeds 60%, analyze the ACH occupation
according to the registrations and call attempts, and determine
frequency registrations or frequent accesses originated by the user
results in the high ACH occupation.
If it is caused by the frequent registrations, modify the registration
parameters and reduce the registrations.
If the user originates frequent access when the traffic is not heavy,
identify the real reasons. Check the operating status of equipment and
eliminate the cause of system abnormality.
Generally, the high ACH occupation is caused by incorrect settings of
LAC zone parameters, or system operation abnormality.
For details, refer to section 2.3.3Alarm Data Analysis and section
2.3.5Parameter Checking.
Many call resources allocation failure
RSSI exceptional is caused by equipment abnormality, for example,
transmission or BSC resource allocation module failure, and many
calls are rejected frequently, result in the repeated calls.
There are too many network busy hour attempts, for example, over
3000 attempts. The traffic statistics or CSL shows that many calls are
released abnormally.
If the allocation of many call resources fails, the ACH load may be also
high.
Check whether many calls are rejected because of the transmission,
www.TempusTelcosys
12. CE configuration, FMR resources, SPU load or roaming restriction.
Through the previous operations, RSSI is restored to a normal value,
and the process ends. Otherwise, conduct the next round.
2.3.3 Alarm Data Analysis
Check the alarms, such as RSSI main/diversity received channel fault
alarm, TRM main/diversity comparison exceptional, or standing wave
alarm.
If these kinds of alarms are available, check the alarm date and the
association between RSSI exceptional and alarm data.
If the RSSI exceptional is associated with the alarm data, RSSI
exceptional may be caused by the equipment faults.
To locate the problems, do as follows (before performing the following
operations, check the regularity of RSSI exceptional and perform the
following operations when the RSSI is exceptional):
1) Trace the RSSI of base station through TELNET. 10 minutes later,
check the change of RSSI and find the regularity.
2) If the RSSI is exceptional, check the connection cables and screws
of DDU, power amplifier and TRM at near end are secure. Check
whether RF cables are damaged and the connectors are secure.
Ensure the antenna SWR is within the receivable range.
3) Check the DDU, power amplifier, and TRM at near end. If the
indicators flash abnormally, reset and insert or remove the units and
observe the status.
4) Trace the RSSI of base station through TELNET. 10 minutes later,
save the records, and analyze whether RSSI is changed or is
restored to a normal value.
5) If RSSI is still exceptional, conduct the next round.
Main/diversity received channel fault mechanism checks the
main/diversity RSSI and reports the alarm. The alarm report depends
on the difference between main RSSI and diversity RSSI and the
difference duration. In different versions, the alarm thresholds of these
two input values are also different.
2.3.4 Historical Operations Analysis
Check the historical operation records of RSSI exceptional cell and
observe the added or modified base station hardware and the changed
data, and the association between the interference occurrence time
and operation time.
If the carrier is conducted within the near end time and RSSI
exceptional time is associated with the operation time, the RSSI
www.TempusTelcosys
13. exceptional is caused by this operation.
The RSSI rise may be contributed to the upgrade, parameter
adjustment and RF adjustment.
Upgrade
The RSSI exceptional caused by the upgrade mainly represents the
BSC upgrade. If the RSSI is increased after the BSC is upgraded,
check the change of parameters before and after upgrade, and restore
the changed parameters to the parameters before upgrade as
possible. Check whether RSSI is restored to a normal value.
Parameter adjustment
The RSSI rise may be caused by the parameters, such as
TOTAL_ZONES, ZONE_TIMER, initial access power control
parameter, and baseband gain.
RF adjustment
Check whether the RSSI rise time is associated with RF adjustment
time. If yes, check the change of traffic. If the RSSI exceptional is
caused by heavy traffic, exploit the potentials of existing network or
consider network expansion to reduce the carrier load and realize the
load sharing.
When the traffic is not changed, check the antenna and feeder are
connected securely.
If the RSSI is restored to a normal value, the process ends. Otherwise,
conduct the next round.
2.3.5 Parameter Checking
The inappropriate parameter settings also may result in the RSSI rise.
When the RSSI is increased, check the following parameters:
A. Initial access power parameter: If this parameter is set too large,
MS transmits at large power when accessing a network. As a
result, the noise floor and RSSI are increased.
B. TCH minimum gain: If the TCH gain is too large, the terminal
transmits large power over TCH. As a result, the voice quality is
improved, and the RSSI is increased. If the TCH gain is set too
large, it has a small impact on the voice quality, but the system
capacity and RSSI are affected largely.
C. Inappropriate settings of Reg_zone, Total_zone, and Zone_timer or
Reg_zone setting error result in the frequent terminal registrations.
As a result, the RSSI may be increased.
www.TempusTelcosys
14. D. Open the access macro diversity (some exceptional terminals).
E. Base station layer 2 acknowledgment switch is not enabled (mainly
for IS-95 MS).
F. Check the diversity bypass switch (when a sector has two
carriers).
For the settings of parameters A, B, and C, refer to the network
planning common parameters.
For the settings of parameters D and E, refer to Technical Notice No.
[2006] CDMA002--Technical Notice on Enabling BTS Layer 2 ACK
Switch and Technical Notice No. [2006] CDMA003--Technical Notice
on Disabling Access Macro Diversity Switch.
2.3.6 Antenna and Feeder Checking
Exchange the antenna and feeder of adjacent two cells, and check
whether the high RSSI is caused by the antenna and feeder.
For the omnidirectional sites, exchange the main antenna and feeder
with diversity antenna and feeder, re-trace the RSSI.
After the antenna and feeder are exchanged, if the difference between
main RSSI and diversity RSSI is changed, the RSSI exceptional may
be caused by antenna and feeder or external interference.
Check the antenna and feeder, for example, the lightning arrester is
not damaged, and the connectors between jumper and feeder and
between the jumper and antenna are secure, and then check the
change of instantaneous RSSI.
After the antenna and feeder are exchanged, if the difference between
main RSSI and diversity RSSI is not changed, the RSSI exceptional
may be caused by CDDU, TRX, and HPA or external interference.
Block the carriers, and check the change of RSSI.
After you block the carriers, if the difference between main RSSI and
diversity RSSI is small, the RSSI exceptional may be caused by TRM
or other hardware.
Through the previous operations, if the RSSI is still high, the RSSI
exceptional is caused by external interference, and conduct the
external interference testing.
2.3.7 Interference Testing
The external interference may interfere to surrounding sectors. As a
result, the RSSI values of surrounding carriers are increased.
Thus, before the interference testing, import the site informaiton by
using the Mapinfo, and check the areas to which the RSSI exceptional
cell points. According to the point direction of RSSI exceptional cell,
www.TempusTelcosys
15. locate roughly the position of interference source and then use
YBT250 to find the interference source.
For the procedure of identifying external interference, refer to
Interference Analysis Guideline.
2.3.8 Summary and Conclusions
This section examines the analysis of reverse RSSI exceptional. If the
personnel are sufficient and the customer has a high requirement,
analyze the RSSI exceptional through several procedures at the same
time. For example, in the equipment room, when the engineers can
check alarms, they can check the parameters and analyze the traffic
statistics. The field engineers can identify the interference through the
RSSI tracing at near end, antenna and feeder adjustment and
interference testing, together wit the engineers in the equipment room.
www.TempusTelcosys
16. 3 RSSI Exceptional Troubleshooting
Forward and reverse interferences degrade the network quality, so we
must assist the customer to eliminate the interference.
If the interference is determined, do as follows:
3.1 Interference Testing
Test the forward and reverse interferences according to the
Interference Testing Guideline.
3.2 Interference Data Analysis
Analyze the collected information, and locate preliminarily the reasons
of RSSI exceptional (too high or the difference between main RSSI
and diversity RSSI is large).
If the RSSI exceptional is caused by non-external interfere, identify
different solutions regarding to different reasons.
If the RSSI exceptional is caused by external interference, determine
the interference characteristics, interference types, and the
interference occurrence regularity, and confirm the interference type,
such as inband interference or outband interference, stable broadband
interference or burst interference.
On the forward link, make the quantitative analysis according to the
specific interference.
www.TempusTelcosys
17. 3.3 Determining Interference Troubleshooting
Solution
If the RSSI exceptional is thought to be caused by equipment fault,
disable the transmit power of power amplifier or exchange the main
antenna with diversity antenna.
If the RSSI exceptional is caused by external interference, use YBT250
to identify the interference according to the interference characteristics,
and determine the interference source.
For the procedure of interference testing, refer to
YBT250 User Manual.
3.4 Eliminating Interference
After the interference source is located, use the relevant measures to
eliminate the interference. If the RSSI exceptional is caused by
equipment fault, replace the equipment.
If the high RSSI is caused by parameter setting errors, modify the
parameters.
When other external interference sources are located, ask the wireless
committee to clear the frequency if necessary. If the frequency
clearance cannot be conducted because of some reasons, optimize
the RF, that is, increase the antenna uptilt or reduce the antenna
height or add base stations if necessary to shorten the cell radius and
decrease the interference.
This method is applicable to the dense urban and is not applicable to
the wide area coverage in rural.
3.5 Verification
Confirm whether the interference is eliminated through RSSI analysis
and dialing tests.
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