Evolution from 2G to the future is mirrored each time with significant changes in mobile access technologies, which compels operators to upgrade their networks again and again. However, repeated hardware-based upgrades bring with significant challenges, and have led operators to question - whether this describes the most effective and economical way of achieving network modernization?
A new platform is required
Wireless network integration represents an inevitable trend that subsumes a transition from multidimensional competition. To enhance this process, Huawei has proposed a unique base transceiver station (BTS) platform strategy which merges the platform and design of its wireless products for various systems.
Including BTSs and base station controllers (BSCs) for GSM, UMTS, CDMA, and WiMAX networks, the concept focuses on the advantages of individual products and integrates them to form a product series that harmonizes pattern, architecture, installation and maintenance.
The future oriented, IP-based BTS platform delivers high capacity and powerful data processing capability via fewer, smaller modules that are fully concordant with inevitable technical development trends. Currently, all GSM, UMTS, CDMA, and WiMAX series' BTSs are based on this new integrated platform. Meanwhile, the BSCs of all systems are deployed under an advanced new platform that incorporates All-IP hardware architecture and expands both capacity and reliability. The unified dual-star and dual-plane switching network meets mobile network development needs via its powerful switching capability, high board reuse rate, modular design, flexible service combination, and easy expansion and evolution potential.
From GSM to UMTS to HSPA or HSPA+, and finally to LTE, cabinet replacement is not necessary to upgrade a network, and only a corresponding baseband processing board is needed. Likewise, the radio frequency (RF) component adopts software defined radio (SDR) technologies, and only requires software upgrades in order to support different systems. Since the baseband processing boards for GSM, UMTS, and LTE systems are all the same size, different boards can be mix-plugged into the same cabinet, with different systems supported.
One BTS can be configured with two RF components that support both 2.1GHz and 900MHz and share the same baseband. As a result, an idle GSM 900MHz band can be used for deploying a 3G UMTS900 network, thus realizing significant human and material resource savings that would be otherwise required for tasks such as surveying and installation. Quicker deployment and commercial application can be therefore achieved. In addition, it is possible to use one BTS to construct networks on two bands for operators who utilize both core and extension bands. One is allocated for voice services and the other for data, and this is especially beneficial to 3G operators who only have a bandwidth of 5MHz on a particular band.
How to carry it out?
As a manufacturer capable of providing multiple wireless access products, Huawei has for some time prioritized multi-system integration and has made a significant commitment to its R&D. Its long-term experience in this field has solved a broad range of difficulties, leading to the launch of its platform-based multi-system integrated BTS that has laid a solid foundation for multi-system integration.
Design represents an important consideration for a multi-system integrated BTS platform. A BTS is composed of a few modules, which are shared by different systems and possess identical specifications such as weight and size. A UMTS BTS, for instance, features just three types of basic modules: the base band unit (BBU), the remote radio unit (RRU) for Distributed BTSs, and the radio frequency unit (RFU) for cabinet BTSs. These can be combined in different ways to become BTSs of specific patterns that can cater to different scenarios.
Broadband networking is an inevitable trend for the future development of mobile networks, not least because it provides higher transmission rates, enhanced user experience, and a wider data service application range. Accordingly, the requirement for transmission bandwidth will increase, meaning that traditional E1s and SDHs will fail to meet data service requirements for transmission resources. IP transmission fills this gap as it not only reduces network construction costs, but is also capable of providing wider transmission bandwidth, higher transmission efficiency and easier transmission resource acquisition. Wireless access network equipment must support IP transmission, and Huawei leads the industry in terms of its All-IP solution. All interfaces support IP transmission, thus facilitating transmission network construction, and IP technologies are utilized for internal BTS and BSC switching modules. This greatly enhances switching capability, lowers internal switching complexity and elevates product reliability.
From the modular design, it can be seen that the essential aspect of the integrated BTS platform is its distributed architecture, which refers to both the Distributed BTS that comprises BBU and RRU, and the cabinet-type BTS that comprises BBU and RFU. These have a common feature in that the previously inseparable baseband and radio frequency modules are divided into two parts, thus forming distributed architecture. This decreases construction costs and OPEX, and allows the wireless access network to become smaller, develop more effective coverage, and offer more flexible installation and greater environmental adaptability. The distributed and cabinet-type BTSs complement each other and support both distributed and centralized installation, alleviating site deployment difficulties for operators and increasing implementation speed.
Large capacity and high integration
A multi-system BTS must have different baseband boards to process the related baseband components to support different systems. If each baseband board is not highly integrated and has limited capacity, the restricted baseband slots can support fewer subscribers. This is obviously unacceptable to areas with continually increasing mobile subscriber penetration rates, but Huawei's technical progress has realized baseband board integration and raised their capacity, and thus paved the way for the launch of its multi-system BTS.
Wireless technologies are undergoing continuous and rapid innovation coupled with the move towards upgraded BTS technology that will respond to a new generation. Viewed from the development process of the BTS itself, its products will become adaptable to various complex wireless environments. Macro BTSs will develop as all-modular, which will simplify their configuration in a manner that resembles laying bricks, thus greatly expediting expansion and upgrade convenience. The flexible Distributed BTS alters traditional network construction modes in a way that gives it a leading role in various complex wireless environments and, in compliance with development orientation, Huawei's multi-system integrated BTS platform demonstrates its superiority in a number of ways.
Multiple: Future mobile networks will differ from the 2G models that provide only voice services. Data services may coexist with voice services or even substitute the latter completely, hence creating a multi-system coexistent environment for access network. The integrated BTS platform that supports multi-system integration will naturally surpass any others.
Efficient: Rapid network construction reflects a key requirement for operators. The BTS platform boasts numerous benefits with its modular design, high performance, light weight, small size, ease of site selection, convenient installation, flexible deployment and low configuration costs. Its construction time is reduced by about a third in comparison with the traditional macro BTS, and it will inevitably garner the favor of the majority of mobile operators.
Enhanced: High performance is prerequisite for network operations. The BTS platform features high integration, large capacity and IP architecture so that it assures a mobile network that delivers effective coverage, excellent performance, high reliability and abundant services.
Economical: Saving investment and maintenance costs is a particular priority for operators when site resources are lacking, given the context of network coverage and performance in terms of multiple service provision. Thus, selection of a wireless BTS that complies with development trends has emerged as a key concern for operators.
Multiple system coexistence represents the future mobile network developmental pattern. Many operators have become aware that hardware upgrades do not form the most economical and effective method. Huawei's multi-system integrated BTS platform allows software upgrades to support a network's smooth evolution, and its superior "Multiple, Efficient, Enhanced and Economical" characteristics have raised the bar with respect to multi-system integration.