Exploration and Practice of the site based on the multi-mode RRU building environmentally efficient room

[Abstract] article first introduced the background of the project and construction of environmental protection and efficient room divided advantage of the site to explore the construction of many sub-sites, based on a new multi-mode RRU efficient room can solve the original model, and then by the actual case effectively enhance site performance, and improvement chamber sub-site profitability.

[Keywords] multi-mode RRU energy saving room sub-site 1 Overview With the maturation and integration of the further development of China Unicom's 3G network and wireless broadband services, mobile networks have to enter the full-service operation mode, the need for new networking technologies to achieve Unicom network multi-standard, multi-service converged coverage to achieve the requirements of the "single-system multi-network operators.

Explore and practice environmentally efficient new room sub-site, in the room sub-site design, property coordination, equipment for the construction period, engineering and maintenance costs, network optimization to improve efficiency, increase the room sub-site revenue, to meet a variety of network parallel operation needs.

2 Project Background Shenzhen Unicom, for example, the full-Shenzhen has room over 3700 sub-sites, including GSM and WCDMA Total Station Room sub-site about 2000, as well as part of the site, superimposed on a Wi-Fi network .2 G, 3G distributed source up to more than 4,000 sets of huge expenses, property costs, electricity sub-site solutions based on a new type of multi-mode RRU efficient environmental chamber provides a new way to enhance the performance of chamber sub-sites.

Combination of Unicom's existing network, multi-mode RRU to achieve 2G/3G/WLAN device integration in order to achieve a one-time fast network, to avoid the multi-system repeat construction, to mitigate the impact of the environmental landscape, improve construction efficiency, reduce property difficult to coordinate improve resource utilization, reduce the power consumption of the device, so that the tradition of single-mode networking into energy-efficient multi-mode networking mode, as shown in Figure 1.

3 building environmentally efficient room sub-site of the advantages 3.1 of new environmental chamber sub-site of the characteristics of multi-mode RRU at the same time support the DCS and WCDMA of digital RRH, and also support the WLAN baseband transmission. The system directly coupled base station signal, using digital transmission signal transmission to the remote coverage. sent back to the mobile communication base station opposite process in accordance with the above procedure, the signal from the mobile phone users received by the remote user antenna of the product is based on fiber optic transmission of digital IF technology, can effectively overcome the analog The disadvantage of the deterioration of the SNR of the signal in the optical fiber transmission, the advantage of having a large dynamic, low-noise.

Multi-mode RRU block diagram shown in Figure 2:

System consists of digital access control unit (DAU and digital radio far consisting of unit (DRU DRU can support both WCDMA and two standard RF DCS digital zooms out, that is traditional devices need the different multiple devices to support a variety of standard multi-mode RRU RRH units at only need a single device can support. DRU to support both WLAN baseband transmission, fiber optic interconnection between DAU and DRU.

3.2 new environmental chamber sub-carrier and RF advantage of the site multi-mode RRU carrier frequency selection conducive to filter out unwanted carrier power to reduce interference with multi-carrier support to ensure its source with the base station equipment compatibility, which will help system expansion.

Judging from the RF characteristics, multi-mode RRU DCS system gain of 50dB, the maximum RF output power of 48dBm (60W WCDMA system gain to 50dB Maximum RF output power of 46dBm (40W. multimode the RRU has higher RF power can be effectively resist the system attenuation, a larger area of ​​coverage, which will help reduce the number of new source, thereby reducing the source of investment.

3.3 new environmental chamber sub-site networking advantages of multi-mode RRU system supports star, daisy-chain as well as Hungezuwang way to achieve a drag application form. Multiple Zuwangfangshi flexible application, can be effective in reducing the transmission resources occupied .

The multi-mode RRU system network diagram is shown in Figure 3.
In addition, DRU support optical bypass function, you can ring networking.
Bottom noise off 3.4 points to the new environment-friendly rooms site and delay calibration advantages of multi-mode RRU system with uplink noise floor off. Feature uplink idle channel intelligent Close intelligent open channel, and then when the business needs, lower uplink noise can be in the form of a trailer and more.

Multi-mode RRU along with automatic and manual delay calibration function. Chain structure different DRU between, between the DRU source RRU overlapping coverage areas, there is a certain delay between them, when the extension of the larger When these overlapping coverage areas will appear the phenomenon of co-channel interference. use of multi-mode RRU delay calibration function, which can effectively prevent co-channel interference, Links to free papers Download Center http://eng.hi138.com
3.5 The site of energy saving advantage in the new environment-friendly rooms, multi-mode RRU Remote power consumption of 400W, integrated GSM network and WCDMA network, but remained lower power consumption. of singlemode networking with multi-mode networking power consumption on such as shown in Table 1.

Where, electricity is calculated in accordance with 1.2 yuan / kWh. Seen from Table 1, new Website multimode networking effective energy-saving up to 36%, the annual electricity savings of 2,014 yuan a single station. The replacement of old equipment for multi-mode devices, the effective energy-saving up to 45%.

4 use of new environmental program example 4.1 alternative Peng Lai Building, located in the Futian District, Shenzhen, close to Binhe Shenzhen high-rise commercial and residential buildings have to do the distribution system. MicroCell original distribution system (set, power consumption 550W GSM analog fiber optic repeater (set power consumption of 450W, WCDMA RRU (a power consumption of 450W, dry place (two sets of power consumption of 140W, 1590W total power consumption alternative to replace the original using a multi-mode RRU GSM Fiber Repeater and WCMDA RRU MRRU remote machine (a power consumption of 400W, dry place (two sets, the power consumption of 140W, 540W total power consumption.

The Peng Lai Building multi-mode RRU alternative is shown in Figure 4.
4.2 investment in the energy consumption analysis of a power consumption data acquisition Pengli Tower after the replacement of the multi-mode RRU before replacement data, as shown in Table 2.

Comprehensive Table 2 data, the total power consumption of all system equipment nominal power consumption day 1.590 × 24 = 38.16 degrees, the actual average electricity consumption is 39.28 degrees, with the aging of the equipment resulting in reduced efficiency related to the replacement of equipment, equipment from The average daily consumption dropped to 39.28 degrees to 14.27 degrees, by 1.2 yuan / kWh, an annual savings of $ 1.2 × 25 × 365 = 10950 per set, to achieve a good energy saving effect.

4.3 coverage effects assessment RRU replaced before and after the Peng Lai Building multimode WCDMA RSCP contrast as shown in Figure 5 (see next page after the replacement of the multi-mode RRU coverage area RSCP>-65dBm ratio increased from 61.67% to 97.13% an increase of 35.46%, the RSCP of the coverage area of> =-85dBm 100%.

The Panny Building multi-mode RRU replaced the GSM RxLev before and after contrast, as shown in Figure 6 (see next page, the replacement of the multi-mode RRU the coverage area RxLev>-65dBm ratio from 78.16% to 98.95%, 20.79% The coverage area RxLev> =-85dBm 100%.

4.4 Summary Peng Lai Building energy saving replacement pilot not only fully demonstrates that multi-mode RRU networking has a huge energy saving advantages compared to traditional networking mode, and verify the new site to be able to cover the effect is even better than traditional equipment room divided .

5 Conclusion multi-mode RRU novel room can effectively solve the large room sub-site and district integrated covering the site with high energy consumption, while improving the profitability of the room sub sites and site performance. Transformation in the original GSM rooms site 3G only site program. need to use multi-mode RRU put on the original GSM dry, or RRU replace, need to be increased property occupies and electricity overhead.

Construction of the new chamber sub-sites, based on multi-mode RRU is an energy-efficient network construction mode. Use its good performance not only "open source", you can also "throttle", extended profit gains space can be expected, as the network technology the continuous development of energy-efficient multi-mode RRU the networking mode will play an increasingly important role.


[1] Sun Yutong WCDMA air interface technology [M] Beijing: People's Posts and Telecommunications Press, 2011. Posted in the free papers Download Center http://eng.hi138.com

Communication Science Papers