Huawei Communicate
Get ready for 900MHz refarming 900MHz refarming solutions based on Huawei’s SingleRAN let operators use the GSM frequency to quickly deploy a low-cost UMTS network with wide coverage. Users get seamless 2G and 3G services with two networks integrated on the same platform. By Li Chunlin
service (QoS) is improved and better user Due to the advantages o a UMS900 experience enabled. network, increasingly more countries have When constructing a UMS900 begun to ormulate policies regulating network, operators can protect their the deployment o 3G networks on the investment in the original GSM network 900MHz band. UMS network can be he EU passed a new resolution on constructed in the GSM900 by reusing inrastructures like the antenna and site. July 27, 2009, approving rearming the requency band at a lower cost However, due to limited spectrum 900MHz band and requested that its with better coverage than a resources on the GSM900 band, most member countries enorce the bill within UMS2100 network. six months to drive the development o According to radio wave propagation operators cannot provide a complete 5MHz requency band to build the the 3G mobile communications industry. eatures, radio signals are transmitted UMS network. In addition, the existing 900MHz operators can utilize the arther at a lower carrier requency and GSM900 network has accumulated a large requency or any technology, at their own allow one site to cover a wider area. Tis subscriber base and is an important source discretion, without license restrictions. makes the UMS900 an excellent wide o proits or operators. his is why the coverage solution. hereore, investment GSM/UMS 900MHz rearming solution or mobile networks goes down as wider SingleRAN based was proposed in the hope o constructing coverage per site means ewer sites. Second, the UMS900 network is low-cost UMS900 networks with refarming solutions wide coverage and implementing joint better or indoor coverage and has better When perorming 900MHz rearming, networking between UMS and GSM network coverage perormance. Lowoperators need to address the ollowing networks while ensuring the continuous requency carrier signals suer less loss our key issues: 1) he intererence when penetrating building walls. hus, capacity expansion and QoS o the GSM between GSM and UMS networks must network. with a UMS900 network quality o
900MHz refarming: a growing trend
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Solution Get ready for 900MHz refarming
be minimized; 2) Feeder and Antenna sharing to protect existing investment; 3) Guarantee o GSM network capacity enhancement and continuous development; 4) Unied operation and maintenance o the two networks to reduce OPEX. As a leading Next Generation Mobile Network solutions provider, Huawei has launched innovative SingleRAN solutions based on 4th generation base stations. Huawei then releases its end-to-end commercial SingleRAN based rearming solutions, which eectively address the our key issues above.
GSM/UMTS site sharing solution For GSM/UMS joint networking, two scenarios can be applied: site sharing and non-site sharing. As the coverage radius o a UMS network is larger than that o a GSM network, in the non-site sharing scenario, the number o UMS sites can be reduced and equipment investment thus less. Tis also has some disadvantages. First, sites are not shared and network deployment cannot be perormed as per the original cellular structure. Te original GSM site resources cannot be completely utilized, which will give rise to a large number o new sites and cost more or auxiliary equipment. Second, when the GSM and UMS networks do not share sites, the intererence between GSM and UMS networks will increase. In the site sharing scenario, intererence between GSM and UMS networks is reduced, and operators do not have to construct new sites, saving money on auxiliary equipment. By adjusting the transmitted power o the UMS network, the GSM coverage area and that o UMS networks may be basically the same. When antennas are not shared, by adjusting the downtilt angle and azimuth, each network can achieve the best coverage perormance. he Huawei SingleRAN based 900MHz rearming solutions can eectively meet the site sharing requirements or GSM/UMS joint networking. Also, the GSM and UMS networks can use the same RF module through sotware upgrades and cut equipment costs.
Adjacent requency guard band solution Huawei SingleRAN based requency rearming solutions mainly support two types o requency allocation: edge-type and sandwich-type allocation. Figure 1 shows the edge-type GSM/UMS requency allocation method. Frequency gap (1) between the GSM band edge and the center o the UMS band can be congured based on the gap requirement o the product. For 2, the requency gap with other carrier’s band must
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be no less than 2.6MHz. I less than 2.6MHz, the other carrier’s GSM network, given its unknown RF perormance, may interere with the UMS network, especially when the system is used on the Broadcast Control Channel (BCCH) or Packet Data Channel (PDCH). Since the power control is disabled, more intererence will be generated on the UMS. For the requency gap 1, Huawei SingleRAN based 900MHz rearming solutions support a minimum bandwidth o 2.4MHz in urban areas and 2.2MHz in rural. For the requency gap 2, i the adjacent requency is idle, the solutions support a minimum bandwidth o 2.5MHz. I the adjacent requency is occupied as other carrier’s GSM band, the bandwidth spacing must be no less than 2.6MHz. Figure 2 shows the sandwich-type GSM/UMS requency allocation. Within the carrier’s requency band, the UMS requency is placed in the middle, with GSM requency band on its two sides. he requency gap between the center o UMS and the GSM on its two sides, is equal and can be congured based on the gap requirement o the product. I 1 and 2 are equal and both are less than 2.6MHz, the requency bands on two sides o the UMS can share spectrum resources with the GSM system. Compared with edge-type allocation, this method doubles the number o the GSM carrier spectrums. According to sandwich-type allocation, the UMS carrier spectrums can be placed anywhere within the spectrum o the operators (not necessarily the center o the spectrum). Tis can be determined based on the operation strategies o the operators. For example, the carrier may split some spectrums in the uture to obtain 2 UMS bands, which can reduce subsequent UMS requency adjustments. For the requency gap o 1 and 2, Huawei SingleRAN based 900MHz rearming solutions support a minimum bandwidth o 2.4MHz in urban areas and 2.2MHz in rural.
Co-requency bufer zone solution When the UMS and the GSM networks use the same requency band, the signal o base stations or terminals in one system alls within the reception area o the other system. Tis intererence cannot be suppressed by the receiving ilter. Instead, only an appropriate requency buer zone can be set between the two systems within the same requency band to accelerate attenuation o the interering signal and guarantee normal operation o the two systems. For this purpose, Huawei has developed an innovative co-requency buer zone solution, resolving co-requency intererence between two
Huawei Communicate
systems. he solution has been put into successul commercial use by Optus in Australia.
GSM system
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GSM system of other operators
UMTS system
Bringing multiple values Huawei’s SingleRAN based 900MHz rearming solutions bring value in our major ways: First, they optimize the RF lter o base stations and use an advanced algorithm to provide requency rearming solutions or small requency spacing in various scenarios minimizing the impact o the UMS900 on existing GSM by making ull use o scarce 900MHz requency resources. Second, by adopting SDR technology, Huawei SingleRAN-based 900MHz rearming solutions enable the GSM and UMS to output signal on one power ampliier and share antennas naturally, reducing the network construction costs. hird, with the Huawei SingleRAN based 900MHz requency rearming solutions, GSM and the UMS networks are ully integrated on the same hardware platorm. Co-RRM (co-radio resources management), Co-O&M (Co-operation & maintenance), and Co-RNP/RNO (Coradio network planning/radio network optimization) are realized with sotware, consolidating the two independent networks to allow users to enjoy high-end 2G and 3G services without a hitch. By using GSM/UMS Co-RRM, radio resources o various standards can be fexibly allocated, with channel allocation, power control and handover policy under various standards optimized based on service and capacity requirements to maximize the utilization o radio resources. With GSM/ UMS Co-O&M, a unied operation & maintenance interace, coniguration control commands, as well as normalized measurement reports and statistics reports can reduce the complexity and cost o maintenance. With the GSM/ UMS Co-RNP/RNO tool, planning and optimization o the GSM and UMS networks can be carried out in a uniied way to improve the accuracy o network planning, and boost construction o high-quality networks, while reducing
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Fig. 1 Edge-type GSM/UMTS frequency allocation
GSM system
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GSM system
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Fig. 2 Sandwich-type GSM/UMTS frequency allocation
maintenance costs. Tree vendors in the industry, including Fourth, the improvement o network Huawei, have successully developed a p e r o r m a n c e a n d t h e s u s t a i n a b l e commercial UMS900 network. So ar, development o the GSM network can be Huawei has constructed and released more assured. than three GSM900/UMS900 SDR Huawei has independently developed a commercial networks. en UMS900 series o technologies or intererence prenetworks in the industry have been put elimination and intererence reduction. into successul commercial use and at least hey can eectively improve network 60 UMS900 networks are being planned perormance, increase network capacity, or deployed in 2010. enhance spectrum utilization eiciency, erminal vendors are speeding up the R&D improve user experience and increase and manuacturing o UMS900 terminals. revenues. Consequently, the capacity According to a survey by Global mobile and quality o the GSM network can Suppliers Association (GSA), 34 terminal be improved despite limited spectrum vendors in the world have released 190 resources. UMS900-HSPA terminals, including 118 he tight requency reuse solution UMS900-HSPA mobile terminals and 39 rom Huawei, together with the optimized USB dongles. Routers, PC cards and built-in channel allocation policy, can eectively modules that support the UMS900 have also reduce and suppress network intererence, been commercially released and all UMS900 increase system capacity by up to over terminals support GSM/EDGE unctions. 200% with limited requency resources In Europe, Middle East, Arica and and guarantee voice quality o the entire the Asia Pacic region, the UMS900 is network. his is especially helpul in becoming a standard terminal requency. scenarios with low network capacity, high Growing mobile broadband service traic and an insigniicant improvement demands, deregulation o telecom policies rom requency hopping. on 900MHz, as well as the launch o a large number o terminals means that increasingly more UMS900 requency Commercially mature rearming networks will be operational. Editor: Liu Zhonglin
[email protected] environment
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