Download - WCDMA 3G2G Co-site Solution
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HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential
Security Level:
47pt
www.huawei.com
Huawei 2G3G Co-Site solution
Huawei Northwest Africa Region
RNP Solution manager: William.chen
E-mail: [email protected]
For Tunis Telecom
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Page 2Huawei Confidential
Overview of 3G2G Co-site
Interference Analysis of 3G2G Co-site
Solution to 3G2G Co-site
Application Examples of 3G2G Co-site
Agenda
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Page 3Huawei Confidential
Reduce the construction cost and rental cost of sites and save the construction cost and rental cost of antenna feeders.
Speed the construction of the 3G engineering and put 3G into operation quickly, seizing more market opportunities.
Avoid the negotiations with building managers during the course to obtain base stations and much unnecessary work.
Purpose of Shared Site Addresses
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Page 4Huawei Confidential
The problems includes:The problems includes:q How to resolve the problem about 3G2G
interferenceq How to resolve the problem about
shared equipment roomsq How to resolve the problem about
transmission sharing q How to resolve the problem about
insufficient sitesq How to
Problems about Co-sites
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Page 5Huawei Confidential
Equipment room
3G base station
Shared feeder
Shared transmission
Storage battery
Power
supply
Air-conditioner
2G base station
Illustration for 3G2G Co-site
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Page 6Huawei Confidential
In the early stage, the GSM/DCS system provides transmission channels for WCDMA.In the later stage, the WCDMA system provides transmission channels for GSM/DCS.
Shared transmission equipment
Consider the condition about the area, load-bearing capacity and power supply of the equipment room when performing the installation.
Shared equipment rooms (including the power supply system and air-conditioner)
Shared antenna feeders --- separated with wave filteredShared feeders
Shared towers --- separately installed vertically or horizontallyShared support poles --- separately installed verticallyShared antenna planes --- separately installed horizontally
Shared installation positions
Contents Involved by Shared Station Addresses and Features
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Page 7Huawei Confidential
Overview of 3G2G Co-site
Interference Analysis of 3G2G Co-site
Solution to 3G2G Co-site
Application Examples of 3G2G Co-site
Agenda
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Page 8Huawei Confidential
Filter ReceiverTransmitter Filter
The interference between systems comes from the
transmitter.
The interference between systems is reflected by the effect on the receiver of the
base station.
The interference problem is the core problem about 3G2G co-site.
Interference Principle
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Page 9Huawei Confidential
The interference of the receiver includes the spurious radiation interference coming from the transmitter, the block interference caused by the signals of the transmitter and the inter-modulation interference generated by the receiver itself.
Spurious radiation
Transmitter ReceiverInter-modulation
Transmission source
Interference Categories
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Page 10Huawei Confidential
It refers to the signals transmitted by the transmitter that are beyond the frequency range specified by the carrier. These signals include harmonic wave components, parasitical radiation, cross-modulation products and inter-modulation products.
Transmission signals
Spurious signals
Spurious Radiation
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Page 11Huawei Confidential
1873MHz1824MHz1824MHz1873MHz 1922MHz
LNA
Inter-modulation
product
Receiver inter-modulation occurs internally in the receiver. There are the following methods to avoid it: Add a suppression filter at the input terminal of the receiver. Adjust the position of antennas to improve the antenna isolation between the interfering system and the interfered system. Improve the linearity of the receiver.
Inter-modulation
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Page 12Huawei Confidential
The receiver usually works in the linear area. When a strong interference signal comes to the receiver, the receiver works in the non-linear state and the signal even causes the saturation of the receiver in the serious condition. This phenomenon is referred to as block. It reflects that the receiver still has the capacity to normally receive and demodulate an expected signal in the condition where there is an interference signal.
RX TX
System A
RX TX
System B
BPF
LNA
BPF
LNAPA
PABPF
Block
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Page 13Huawei Confidential
Signal
Noise
Spurious interference, inter-modulation interference and block interference cause the following problems: background noise rise, SNR value decrease and signal demodulation deterioration. Thus, error rate requirements cannot be met.
In the normal condition, if SNR>-19.4dB, the system can normally demodulate a voice at 12.2kbps.
Background Noise Rise
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Page 14Huawei Confidential
DCS1800 Rx DCS1800 TX WCDMA Rx WCDMA TX
1710Mhz 1785Mhz 1805Mhz 1880Mhz 19200Mhz 1980Mhz 2110Mhz 2170Mhz
GSM900 Rx GSM900 TX WCDMA Rx WCDMA TX
890Mhz 915Mhz 935Mhz 960Mhz 19200Mhz 1980Mhz 2110Mhz 2170Mhz
The interference to 2G has been taken into account in the 3G protocol. Therefore, 3G has a very little interference effect on 2G and the effect can be ignored.
Schematic Drawing of Interference
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2G 3G
Space isolation
Filter isolation
Frequency optimization
Some Methods for Interference Isolation
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Page 16Huawei Confidential
24272427Inter-modulation isolation
GSM900 to WCDMA
WCDMA to GSM900
DCS1800 to WCDMA
WCDMA to DCS1800 Requirement item
-30
39
1212-22In-band block isolation
92 92 38Spurious isolation
Typical isolation numerical value (dB)
The suppression effect of the transmitter and the receiver on interference is better than that indicated by the indices in the protocol. Moreover, in a practical environment, the isolation between the 3G and 2G is low. Therefore, it is veryeasy to meet the requirements of a project.
Requirements for the Isolation of Protocol
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Page 17Huawei Confidential
Interference Analysis of WCDMA to GSM BS Node B based on test result :
26dBIsolation for 2G/3G Co- siting
10dBIsolation Margin
-134dBm/100KHzMax Interference in WCDMA RX Band
-107dBm/100KHzBTS IM
-119dBm/100KHzMax BTS Spurious in WCDMA RX Band
83dB@1920MHzStandard TX Filter Rejection
-51dBm/100KHzMax PA Spurious in WCDMA RX Band
3900 SeriesGSM BTS Type
In fact most GSM BTS index is better than the protocol, so 30dB isolation degree is enough according to actual network experience .
It is better than protocol actually
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Page 18Huawei Confidential
Overview of 3G2G Co-site
Interference Analysis of 3G2G Co-site
Solution to 3G2G Co-site
Application Examples of 3G2G Co-site
Agenda
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Page 19Huawei Confidential
Shared towers
Antennas are installed at the top of towers or on the raised floors of buildings. In most conditions, antennas can share towers or raised floors without added corresponding facilities.
Shared antenna planes
Antenna planes are the installation planes of antennas. In most conditions, antenna planes can be shared. However, we should check whether the space between antennas meets the requirement of isolation.
Shared support poles
If the lengths of support poles are long enough, antennas can share them. However, we should assure that the vertical isolation requirement between two systems can be met. In most conditions, it is required to add new support poles.
Shared Conditions
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Horizontal Space/Vertical Space definition
Horizontal Space installation Vertical Space installation
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1920 1980
UMTS2100 DLUMT2100 UL
2110 2170
60MHz 60MHz
960880 915
UMTS90 UL UMTS DL
35MHz
925
35MHz
0.5Minimum Horizontal distance (m)
0.2Minimum Vertical Distance at the same pole (m)
35Isolation DegreedB
Interference analysis result according to 3GPP 0505.V8.17.0
GSM900&UMTS2100 Interference Solution
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Page 22Huawei Confidential
1920 1980
DCS1800 DLDCS1800 UL
2110 2170
60MHz 60MHz
18801710 1785
UMTS90 UL UMTS DL
75MHz
1805
75MHz
0.5Minimum horizontal distance (m)
0.2Minimum vertical distance at the same pole (m)
43Isolation degreedB
Interference analysis result according to 3GPP 0505.V8.17.0
DCS1800&UMTS2100 Interference Solution
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Overview of 3G2G Co-site
Interference Analysis of 3G2G Co-site
Solution to 3G2G Co-site
Application Examples of 3G2G Co-site
Agenda
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Page 24Huawei Confidential
Installed on the tower, separated horizontally
Installed on the tower, separated vertically
Mauritius project: sharing the tower of 2G and separated by using antenna direction angles and height differences
Shared Tower Example
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Installed on the top of building, separated vertically
Installed on the top of building, separated horizontally
Hong Kong project: sharing the installation antenna plane of 2G and separated through the horizontal or vertical distance between antennas
Shared Antenna Plane Example
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3G NodeB2G base station
Hong Kong project application, sharing the installation platform of 2G
Shared Outdoor Installation PlatformShared Outdoor Installation Platform
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Page 27Huawei Confidential
In Netherlands, Huawei distributed BBU (baseband processing unit) is placed in the outdoor type BTS cabinets of other GSM manufacturers.
Huawei BBU
Combiner(sharing antennas)
Shared Cabinet Example of BBU and GSM
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Share antenna or not?
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Page 29Huawei Confidential
Separated antenna system is recommended if the installation space is enough
Recommendation solution(1)
GSM900+UMTS2100 GSM900+DCS1800+ UMTS2100
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Co-antenna system is recommended if the installation space is not enough
Recommendation solution(2)
GSM900+UMTS2100 GSM900+DCS1800+ UMTS2100
OR
GSM BTS
UMTS BBU
UMTS BBU
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Page 31Huawei Confidential
Advantages
Disadvantages
Reduce the cost of antenna feeders and make the construction of engineering easier.
Save installation positions by sharing antenna feeders.
Avoid vision pollution and public worries of electromagnetic radiation.
The down tilt angles of shared antennas cannot be adjusted flexibly and the coverage directions are relatively fixed. (If we use theantennas of two systems, the down tilt angles of antennas are adjustable, but the cost is too high.)
For shared antennas, isolation can only implemented by the isolation designed for them. This isolation is usually only 30dB or so. We need add filters to implement the required isolation between systems.
Share antenna or not?
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