HUAWEI BTS3900 Hardware Structure www.huawei.com Copyright © 2009 Huawei Technologies Co., Ltd. All rights reserved. Chapter 1 BTS3900 Product Description Chapter 2 BTS3900 System Structure HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 2 BTS3900 Product Description u The BTS3900 is comprised of the BBU3900, MRFU, and indoor macro cabinet. The BBU3900 and the MRFU are installed in the indoor macro cabinet. The PS4890 meets the requirements of different applications when the backup power or transmission equipment space is required. BTS3900 system structure HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential PS4890 system structure Page 3 Features of BTS3900 u Advanced Platform-Based Architecture Ø Based on the unified hardware platform, the BTS3900 supports three working modes: GSM mode, GSM+UMTS dual mode, and UMTS mode through configuration of different software. In addition, the BTS3900 supports smooth evolution to the Long-Term Evolution (LTE). Ø The RF module integrates the duplexer and the Transceiver Unit (TRU), thus enhancing integrity of RF parts and meeting future requirements for a compact, high-efficiency, and lowcost base station. Ø Supports whole frequency band of PGSM 900MHz, high 45MHz frequency band and low 45MHz frequency band of DCS1800MHz, high 40MHz frequency band and low 40MHz frequency band of 1900MHz. u High Capacity Ø When the BTS3900 works in GSM mode, a BBU3900 supports the maximum cell configuration of S24/24/24. Ø When the BTS3900 works in GSM+UMTS dual mode, a BBU3900 supports the maximum cell configuration of GSM S4/4/4 + UMTS S2/2/2 or GSM S5/5/5 + UMTS S1/1/1. Ø When the BTS3900 works in UMTS mode, a BBU3900 supports 24 cells, 1,536 CEs in the uplink, 1,536 CEs in the downlink, and the maximum configuration of 3 x 8. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 4 Features of BTS3900 u Transmission Sharing Ø Sharing the CPRI port. The CPRI data of the GSM and UMTS networks can be multiplexed on the same optical cable, which reduces the quantity of CPRI ports. Ø Supports co-transmission between the GSM and the UMTS. Sharing transmission resources between the Abis and the Iub interfaces. u Flexible Clock Synchronization Modes Ø Upper synchronization clock, extract clock from Abis/Iub interface. Ø Extract clock from GPS (Global Positioning System). Ø Synchronization with the IP clock, a highly cost-effective clock solution, which can be obtained through software upgrade without additional hardware. Ø Clock phase lock, tracing, and memory functions and free-run synchronization mode. When the clock operates in free-run mode, the system can keep operational for at least 90 days at normal temperature. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 5 Features of BTS3900 u Networking Capability Ø The BTS3900 supports multiple network topologies, such as star, tree, chain, and ring topologies. Ø Supports Flex Abis networking. Ø When working in UMTS mode, the BTS3900 supports ATM and IP dual stack to protect operators' early investment in ATM transport. Ø u Supports optimized transmission on the Abis interface. Low Power Consumption HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 6 Chapter 1 BTS3900 Product Description Chapter 2 BTS3900 System Structure HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 7 Abbreviation Abbreviation Description GTMU Transmission& Timing& Management Unit for BBU WMPT WCDMA Main Processing and Transmission Unit WBBPa WCDMA Baseband Process unit Type A UTRP Universal Transmission Processing Unit UPEA Universal power and Environment interface unit Type A (-48v) BSBC Universal BBU Subrack Backplane Type C (2U) UBFA Universal BBU Fan Unit Type A (2U) UEIU Universal Environment Interface unit UELP Universal E1/T1 Lighting Protection unit UFLP Universal FE/GE Lighting Protection unit CPRI Common Protocol Radio Interface APM30H Advanced Power Module HEUA The Heat Exchange Unit Type A HPMI The Hert Power Monitoring Interface unit HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 8 Hardware Structure of the BTS3900 u Hardware Structure of the BTS3900 (-48V) Ø The BTS3900 cabinet (-48V) uses the external -48V DC input. The DC power is directly led into the DCDU-01 and the DCDU-01 distributes the DC power to each component in the cabinet. Ø The BTS3900 cabinet (-48V) consists of the following components: the MRFUs, BBU,DCDU-01, and FAN unit. You can optionally install devices of 3U in height in the spare space of the cabinet. Typical configuration of the BTS3900 cabinet (-48V) HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 9 BBU3900 Equipment u The BBU3900, which features a case structure, can be installed in a 19-inch-wide and 2U-high indoor space or outdoor protective cabinet. u BBU3900 equipment includes: Ø GTMU Ø WMPT Ø WBBP Ø UTRP Ø UPEU Ø UEIU Ø UELP Ø UFLP Ø UBFA HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 10 Functions of the BBU3900 u As the baseband processing unit, the BBU3900 provides ports for connection between the dual mode base station and the BSC/RNC and between the BBU3900 and the RF modules. u The BBU3900 has the following functions: Ø Provides ports for communication between the base station and the BSC/RNC. Ø Provides CPRI ports for communication between the BBU and the RF modules. Ø Provides USB ports, facilitating the automatic software upgrade of the dual-mode base station when a USB disk is inserted during software installation and data configuration. Ø Provides an OM channel between the base station and the LMT or the M2000 to operate and maintain the base station. Ø Processes uplink and downlink data. Ø Manages the entire dual-mode system in terms of OM and signaling processing. Ø Provides the system clock. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 11 BBU3900 Slots u The slots of the BBU3900 GSM, BBU3900 GU, and BBU3900 UMTS are the same. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 12 Board configuration principles of the BBU3900 GU Board Optional/ Maximum Slot Name Mandatory Number WMPT Mandatory 1 Slot 7 Preferentially configured in slot 7 in the case of a single WMPT GTMU Mandatory 1 Slot 5 and slot 6 Only configuredin slot 5 and slot6 WBBP Mandatory 4 Slot 0 - Slot 3 UBFA Mandatory 1 FAN Only configured in the FAN slot UPEU Mandatory 2 PWR1 o PWR2 Preferentially configured in the PWR2 slot in the case of a single UPEU UEIU Optional 1 PWR1 - Configuration Limitations Only configured in slot 2 and slot 3 in the case of the WBBP that transmits CPRI Signals In the case of less than or equal to four E1s, one UELP is required and installed in slot 4. In the case of more than four but less than or equal to UELP Optional 2 Slot 0 or slot 4 eight E1s, two UELPs are required and installed in slot 0 and slot 4. In the case of more than eight E1s, the SLPU is required and the UELPs are installed in the SLPU. UFLP Optional 2 Slot 0 or slot 4 Preferentially configured in slot 4 UTRP Optional 4 Slot 0 - Slot 4 —— Typical configuration of the BBU3900 GU HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 13 BBU Hardware – GTMU Board u The GSM Transmission, Timing, and Management Unit for BBU (GTMU) controls and manages the entire BTS in GSM mode. It provides interfaces related to the reference clock, power monitoring, OM, and external alarm collection. u Functions: Ø Controlling, maintaining, and operating the BTS. Providing fault management, configuration management, performance management, and security management. Ø Monitoring the fan module and the power supply module. Ø Providing four routes of E1 transmission. Ø Providing CPRI ports for the communication with the RF modules. Ø Distributing and managing BTS clock signals. Ø Providing the Ethernet port for local maintenance. Ø Providing clock output for testing. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 14 BBU Hardware – GTMU Board u Ports on the GTMU panel: Board Port CPRI0~ CPRI5 Connector Type Description Ports for the communication between the BBU and the RF SPF module; support input and output of the optical and electrical signal. ETH RJ45 Port for local maintenance and commissioning Connects the BBU to a routing device in the equipment FE0 RJ45 room through the Ethernet cable to transmit network information. GTMU Connects the BBU to a routing device in the equipment FE1 DLC room through the optical cable to transmit network information. USB USB Enables the automatic software upgrade from a USB disk. TST USB Provides a reference clock for the tester. Provides the input and output of the four E1/T1 signals E1/T1 DB26 female between the GTMU and the UELP or between the GTMU and the BSC. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 15 BBU Hardware – GTMU Board u DIP Switches: DIP Status DIP Switch Description 1 SW1 2 ON ON The E1 impedance is set to 75 ohms. OFF ON The E1 impedance is set to 120 ohms. ON OFF The T1 impedance is set to 100 ohms. DIP Status DIP Switch 1 2 3 4 Description When four 75- ohm E1 links are faulty, all the ON ON ON ON DIP bits of S2 should be set to ON (unbalanced mode) so that the Faults are rectified. SW2 OFF OFF HUAWEI TECHNOLOGIES Co., Ltd. OFF OFF All the DIP bits of S2 are set to OFF (balanced mode) by default in all modes. HUAWEI Confidential Page 16 BBU Hardware – WMPT Board u This describes the WCDMA Main Processing and Transmission unit (WMPT). It is the BBU3900 main control and transmission board that processes the signals and manages the resources for other boards. u The WMPT has the following functions: Ø Providing Operation and Maintenance (OM) functions such as configuration management, equipment management, performance monitoring, signaling processing, and active/standby switchover and providing OM channels connected to the OMC (LMT or M2000). Ø Providing the reference clock. Ø Processing signaling and managing resources for other boards in the BBU. Ø Providing USB ports, one of which facilitates automatic base station upgraded when a USB disk is inserted during software installation and data configuration. Ø Providing four E1s/T1s which support ATM and IP protocols. Ø Providing one FE electrical port and one FE optical port which support the IP protocol. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 17 BBU Hardware – WMPT Board u Ports on the WMPT: Board Port Connector Type Description E1/T1 DB26 connector E1 FE0 RJ45 connector FE electrical port FE1 SFP connector GPS SMA connector GPS antenna ETH RJ45 connector Commissioning Ethernet port USB USB connector USB loading port FE optical port WMPT TEST RST HUAWEI TECHNOLOGIES Co., Ltd. USB connector — HUAWEI Confidential USB testing port Resetting the BBU Page 18 BBU Hardware – WMPT Board u DIP switches on the WMPT: DIP switch DIP Bit T1 Mode 120-ohm E1 Mode 75-ohm E1 Mode 1 ON OFF ON 2 ON OFF ON 3 OFF ON ON 4 OFF ON ON SW1 DIP switch DIP Bit Balanced Mode Unbalanced Mode 1 OFF ON 2 OFF ON 3 OFF ON 4 OFF ON SW2 HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 19 BBU Hardware – WBBP Board u This describes the WCDMA Baseband Process Unit (WBBP) board. It is a mandatory board of the BBU3900 that processes baseband signals. u The WBBP has the following functions: Ø Provides the CPRI ports for communication between the BBU and the RFU, and supporting CPRI ports in 1+1 backup mode. Ø u Processes uplink and downlink baseband signals. There’re two types of WBBP board: WBBPa and WBBPb. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 20 BBU Hardware – WBBP Board u Specifications of the WBBPs: Board Number of Cells Number of UL CEs Number of DL CEs WBBPa 3 128 256 WBBPb1 3 64 64 WBBPb2 3 128 128 WBBPb3 6 256 256 WBBPb4 6 384 384 HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 21 BBU Hardware – UPEU Board u This describes the Universal Power and Environment Interface Unit (UPEU) board. It is a mandatory board of the BBU3900 that converts -48 V or +24 V DC to +12 V DC. u The UPEU has the following functions: Ø Converting -48 V or +24 V DC to +12 V DC that is applicable to the boards. Ø Providing two ports with each transmitting one RS485 signal and another two ports with each transmitting four dry contact signals. Ø u Providing reverse connection protection for power cable connectors. The UPEU is classified into the Universal Power and Environment Interface Unit Type A (UPEA) and the Universal Power and Environment Interface Unit Type B (UPEB). The UPEA converts -48 V DC to +12 V DC and the UPEB converts 24 V DC to 12 V DC. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 22 BBU Hardware – UELP Board u The Universal E1/T1 Lightning Protection (UELP) is a universal E1/T1 surge protection unit. The UELP is optionally installed in the SLPU or BBU. Each UELP provides surge protection for four E1s/T1s. u Port Connector Type Description INSIDE DB25 E1 transfer transmission port OUTSIDE DB26 E1 transmission port The UELP has one DIP switch, which is used to select whether the receive terminal is grounded. DIP Switch S1 DIP Status Description 1 2 3 4 ON ON ON ON 75-ohm E1 cable OFF OFF OFF OFF 120-ohm E1 cable or 100-ohm T1 cable HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 23 BBU Hardware – UFLP Board u The universal FE lightning protection (UFLP) board is optionally installed in the SLPU or BBU3900. Each UFLP supports 2-way FE surge protection. Port Location Port Quantity Connector Type INSIDE FE0、FE1 2 RJ45 OUTSIDE FE0、FE1 2 RJ45 HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 24 BBU Hardware – UTRP Board u This describes the Universal Transmission Processing unit (UTRP) board. It is a transmission extension board of the BBU3900 and provides eight E1s/T1s and one unchannelized STM-1/OC-3. u The UTRP has the following functions: Ø Providing extension Iub transmission ports which support eight E1s/T1s and one unchannelized STM-1/OC-3. Ø Supporting ATM and IP transport. Ø Supporting cold backup. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 25 BBU Hardware – UTRP Board u The UTRP can be configured with different sub-boards to support different ports. u The panel of the UTRP configured with the UAEU or UIEU is different from that of the UTRP configured with the UUAS. ) Panel of the UTRP (with 2 FE/GEs HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 26 BBU Hardware – UBFA Module u This describes the Universal BBU Fan Unit Type A (UBFA) module of the BBU3900. The UBFA controls the fan speed and detects the temperature of the fan board. LED Color Status Description The module is not 0.125s ON, 0.125s OFF registered, and no alarm is reported. Green The module is 1s ON, 1s OFF STATE running properly. No alarm is reported. OFF Red The module is 1s ON, 1s OFF HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential reporting alarms. Page 27 BBU3900 Cable u BBU3900 Cable List: Power Cable E1 Surge Protection Transfer Cable FE Cable HUAWEI TECHNOLOGIES Co., Ltd. CPRI Optical Cable HUAWEI Confidential Page 28 BBU Cable u BBU3900 Cable List: (1) RJ45 connector (2) cold-pressed terminal (3) ring terminal (4) 3PIN connector Monitoring Signal Cable Between the OFB and the BBU (1) RJ45 connector Monitoring Signal Cable Between the APMI and the BBU HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 29 (2) cold-pressed terminal MRFU Module u u The MRFU is a multi-carrier RF filtering unit. One MRFU supports a maximum of 6 carriers in GSM mode, 4 carriers in UMTS mode, 6 carriers in GSM+UMTS mode. Functions: Ø Ø Ø Ø Ø Ø Ø Implements the direct frequency conversion technique in the transmit channel, modulates the baseband signals to GSM RF signals; then, sends the signals to the antenna for transmission through the duplex filter after filtering, amplifying, and combining the RF signals. The combining can be performed as required. Receives RF signals from the antenna and performs down-conversion, amplification, analog-to-digital conversion, digital down-conversion, matched filtering. Provides power sharing. Improves the network coverage, reduces the interference and power consumption and save the device cost. Provides power control, reverse power detection. Provides frequency synthesis and loopback test. Generates the CPRI clock, recovers the CPRI clock of lost synchronization, and detects alarms. Provides the function of DPD/BPD. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 30 Logical structure of the MRFU u The MRFU consists of the high-speed interface unit, signal processing unit, power amplifier, and duplexer. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 31 MRFU Board u Size:397.25mm(h)×70.62mm(w)×305mm(d) Weight:10Kg u Ports on the panel: Port Type Label Connector Type Description Port for ANT_RXB DIN connector Connecting to the antenna subsystem. SFP female connector Connecting to the BBU, or the upper-level RFU during the cascading. transceiving ANT_TX/RXA RF signals CPRI CPRI0 Connecting to the lower-level RFU during the cascading. CPRI1 Interconnection port RX_INB for RF QMA female connector Input port of diversity signals in the antenna channel. Receive signals RX_OUTA Power supply port PWR 3V3 power connector Feeding power. Monitoring port MON RJ45 connector RS485 Monitoring、debugging port. HUAWEI TECHNOLOGIES Co., Ltd. Output port of diversity signals in the antenna channel. HUAWEI Confidential Page 32 The main limitation of MRFU u MRFU supports whole frequency band of PGSM 900MHz, high 45MHz frequency band and low 45MHz frequency band of DCS1800MHz. High 40MHz frequency band and low 40MHz frequency band of 1900MHz. MRFU DL UL Whole 25MHz frequency band of 900MHz 935-960MHz 890-915MHz Low 45MHz of 1800MHz 1805-1850MHz 1710-1755MHz High 45MHz of 1800MHz 1835-1880MHz 1740-1785MHz Low 40MHz of 1900MHz 1930-1970MHz 1850-1890MHz High 40MHz of 1900MHz 1950-1990MHz 1870-1910MHz HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 33 The main limitation of MRFU u u The instantaneous frequency bands supported by MRFU. MRFU Type Number of TX frequency band of TX Number of RX frequency band of RX GSM mode 1 15MHz 2 25MHz UMTS mode 1 20MHz 2 25MHz GU dual mode 1 15MHz 2 25MHz Power sharing doesn’t support Concentric cell, Co-BCCH, IBCA, RAN sharing while static power can support these functions. u MRFU supports 2-way RX diversity. 4-way RX diversity and TX diversity are not supported. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 34 Configuration principle of MRFU u Basic configuration principle: Ø One MRFU supports a maximum cell configuration of S6. Ø A single BTS3900 provides a maximum of 36 carriers with the maximum cell configuration of S12/12/12. In addition, a site configured with the BTS3900s can support a maximum of 72 carriers with the maximum cell configuration of S24/24/24. Ø One MRFU does not serve two cells. Each cell with a single antenna can be configured with a maximum of two MRFUs. Ø MRFU supports 1-way TX and 2-way RX. Ø Star, chain, and ring, are supported between the BBU and the MRFUs. Ø When star and chain topology is adopted between the BBU and MRFUs, the MRFU supports 3 levels of cascading in a chain and thus the BBU supports a maximum of 18 (6 x 3) MRFUs. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 35 Configuration principle Base on Limitation of MRFU u Assign frequency: Ø If the frequency interval of a cell is outside the range of 15MHz, 2 MRFUs can be considered to be used and the range of frequency for each MRFU also should be within15MHz. Ø Generally, it is suggested that the number of carriers should be set to 2 MRFUs averagely if 2 MRFUs are used in a cell. For example: S8 should be configured as 4+4 when 2 MRFUs are used. S7 should be configured as 3+4 when 2 MRFUs are used. If there’s limitation of frequency band, S8 also can be configured as 3+5 or 2+6. u Frequency hopping: Ø Cell without frequency hopping. The cell can work normally when the range of frequency is within 15MHz for each MRFU. Ø Cell with Baseband frequency hopping. The frequency range of 2 MRFUs must within 25MHz when 2 MRFUs are used. And the range of frequency also must be within 15MHz for each MRFU. Ø Cell with RF frequency hopping. The cell cannot adopt RF frequency hopping if the range of frequency is out of 15MHz. Because the frequency range of 2 MRFUs must be within 15MHz when 2 MRFUs are used. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 36 Configuration principle Base on Limitation of MRFU u Output power: Ø The maximum output power of MRFU is 80W. Ø The output power for each cell must fulfil the requirement of network plan. When the specification doesn’t fulfil the requirement, it can be improved by adding MRFUs. Ø The output power of all the cell must be the same because power sharing is mutually exclusive with concentric cell. For example, S7 configured as 3+4 when 2 MRFUs are used. The output power of MRFU configured as 3 carriers must be the same as that of MRFU configured as 4 carriers. Ø Specifications of output power is Class 2, please refer to the next page. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 37 u Specifications of output power is Class 2: Working mode GSM TRX UMTS TRX Output power of each GSM TRX(W) Output power of each UMTS TRX(W) 1 0 80 0 2 0 40 0 3 0 31 0 4 0 27 0 5 0 18 0 6 0 16 0 1 1 40 40 1 2 40 20 2 1 20 40 2 2 20 20 3 1 24 10 3 1 20 20 4 1 20 10 4 1 17 20 3 2 20 10 3 2 12 20 4 2 13 10 5 1 15 10 0 1 0 60 0 2 0 40 0 3 0 27 0 4 0 20 GSM mode GSM+UMTS mode UMTS mode HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 38 Antenna Configuration of MRFU u Single Feeder. Ø u Two module interconnection. 1TX and 2RX. Double Feeder. Ø Single module. 1TX and 2RX. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 39 Transmit Mode and Receive Mode of MRFU u Transmit Mode of MRFU. Ø u Non-combination. Receive Mode of MRFU. Ø 2-way RX diversity. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 40 Typical configuration of MRFU u Single MRFU. u Double feeder, 1TX + 2RX. Ø When a dual-polarized antenna is configured, one TX channel and two RX channels are supported. The ANT_RXB and ANT_TX/RXA ports receive the signals from the antenna to achieve RX diversity. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 41 Typical configuration of MRFU u Two module interconnection. u Single feeder, 1TX + 2RX. Ø When the cell configuration is from S7 to S12, two MRFUs need to be configured. Ø The ANT_TX/RXA port on each MRFU supports the receiving and transmitting of signals. Two MRFUs provide RX signals for each other through the RF interconnection ports. Thus, the RX diversity is implemented. HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 42 Typical configuration S8/8/8 HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 43 Scenario 1 HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 44 Scenario 2 DCS S888 M R R U M R R U D M R R U D D M R R U D M R R U D M R R U D M R R U M R R U G G APM30 BBU EMUA W R R U W W R R U W W R R U W Base Frame WCDMA S222 HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 45 M R R U G GSM S4/4/4 Summary u Functions of BTS3900 u Hardware structure of BTS3900 u New hardware of BTS3900 u Features and working mode of MRFU HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 46 Thank you www.huawei.com HUAWEI TECHNOLOGIES Co., Ltd. HUAWEI Confidential Page 47