Uni-RAN: A Perfect Way to Modernize Mobile Networks

Demand for Network Modernization

Mobile broadband continues to develop and succeed at a phenomenal pace. The Global mobile Suppliers Association (GSA) confirms that as of May 2011, more than 99.5% of the world’s WCDMA operators have deployed HSPA on their networks, and over 30% of them have evolved to HSPA+. The GSA also anticipates that 81 LTE networks will be in commercial service by the end of 2012 in addition to the existing 20 that have been launched commercially. The rapid growth of mobile broadband has placed high requirements on architecture and management of mobile bearer networks.

GSM/EDGE has by far the largest subscriber base, accounting for more than 88% of global mobile subscribers. Yet most GSM operators are now facing pressure from the growing demand for data services and declining ARPU. Legacy network devices and architecture are barely able to meet the requirements. It is therefore imperative to modernize legacy mobile networks for high profitability and sustainable development.

ZTE's Uni-RAN Solution

To modernize networks, ZTE has developed an innovative Uni-RAN solution that ensures smooth evolution and easy O&M without affecting existing services.

Smooth evolution

Uni-RAN adopts a unified SDR platform that supports multiband and multimode radio configurations. The CN and OMM parts of multiple radio systems are converged in Uni-RAN. This simplifies network architecture and makes network O&M easier and more reliable. By updating software and minimizing changes to hardware, Uni-RAN allows for smooth evolution from GSM/EDGE to WCDMA and then to LTE. In network modernization, it is quite important to balance investment in equipment, network O&M, and network profitability. Because it allows for smooth evolution, Uni-RAN can extend the lifecycle of a network for longer time.  

Flexible networking

ZTE’s SDR base stations come in various types, ranging from indoor macro base stations for dense, high-traffic urban areas to outdoor micro base stations for remote coverage in suburban areas. The advanced BBU+RRU structure is suitable for almost all application scenarios, and installation is also easy and efficient. Compared with legacy indoor macro base stations, the BBU+RRU design saves more than 75% of equipment room. With diverse base stations and flexible networking mode, Uni-RAN helps operators economize on manpower and material resources.

Outstanding performance

Uni-RAN has performance advantages that help operators reduce OPEX, especially transmission and energy costs. The all-IP platform used for SDR base stations greatly enhances communication efficiency and saves on rental fees for E1 transmission. BBUs and RRUs are specially designed to suit different application scenarios. They are small, silent, energy efficient, and naturally cooled. Uni-RAN adjusts transmitting power of RF units according to real-time traffic load. These adjustments are made using software so that power consumption throughout the network is completely optimized. 

Speed Up Network Modernization

By the end of 2010, ZTE had deployed GSM/UMTS networks for 120 operators in more than 100 countries. ZTE’s SDR equipment―the core of Uni-RAN―has been recognized by operators worldwide since it was first launched in 2007. ZTE has achieved large-scale breakthroughs in the global high-end telecom market with the SDR base-station platform. Companies in Europe, such as KPN, Telenor, Telefonica, Optimus and H3G, are using SDR base stations deployed by ZTE. In 2010, the total shipment of ZTE’s SDR base stations exceeded 700,000 units.

Driven by an upsurge in mobile network modernization around the world, ZTE has seized the opportunity to focus on network swapping projects. The company has helped 67 operators in 29 countries modernize their networks, swapping more than 200,000 base station sites. In the first half of 2011, 160,000 GSM/UMTS carriers were successfully swapped by ZTE. Through cooperation with leading operators, ZTE has gained rich experience in network swapping and enhanced capabilities in logistic, engineering, and network optimization.

CSL: create a simple network

CSL is the largest mobile operator in Hong Kong with more than 3 million subscribers. CSL had four original mobile networks: a 900MHz GSM network, two 1800MHz GSM networks, and a 2.1GHz UMTS network. The maximum download rate supported by the UMTS network was only 2.1Mbps, which was insufficient for meeting the requirements of 3G subscribers. Various NMS interfaces were being used to accommodate multiple modes and frequency bands. So CSL had difficulty managing and maintaining individual networks. The complicated network architecture also made it difficult to evolve networks and ensure QoS.

In 2008, CSL chose ZTE as a partner in its network reconstruction. Using Uni-RAN, CSL completely converged its GSM 900/1800M, UMTS 900M, UMTS 2.1G and LTE 1.8G/2.6G networks within two years. Unified network management was also implemented. 2500 base station sites were swapped. The restructured HSPA+ (or Next G) network is capable of downloading data at up to 21Mbps. According to internal research conducted by CSL in 2010, data traffic has increased by more than 65 times since the Next G network was launched in early 2009.  

During the network swapover, CSL cut down the total number of base stations from 5050 to 2050, replaced original E1 transmission with FE transmission, and saved 20% transmission resources. CSL reduced network OPEX by 35.7% and greatly improved its profitability.

Ncell: make a miracle on the Top of Mt. Everest

Ncell is a wholly owned subsidiary of TeliaSonera and is the second largest mobile operator in Nepal. Its network covers 42% of mobile subscribers in the country. Ncell aims to capture the largest market share.

Nepal contains part of the Himalayas, the highest mountain range in the world. Eight of the world’s ten tallest mountains, including the highest point on Earth, Mt. Everest, are located in the country. Deploying base stations on the world’s highest mountain presented big challenges to Ncell.  

For fast deployment and smooth evolution, Ncell adopted ZTE’s Uni-RAN solution in its network reconstruction project. Micro base stations using the SDR platform consume less power, have a small footprint, and are easy to install. A one-piece mast and insulated shelter are used for the stations, and this allows the base stations to be installed quickly without the need to move earth or construct foundations. Solar panels are incorporated into the design to ensure that base stations have power supply throughout the year and are environmentally friendly. These features allow each base station to operate at optimal levels with minimal power usage even in temperatures as low as  30˚C to  40˚C. Overcoming altitude sickness and harsh natural environment, ZTE engineers deployed eight 3G base stations on Mt. Everest one month ahead of schedule.

After 500 base station sites were swapped in the initial phase, Ncell reduced energy consumption by over 45% and saw a rapid rise in their subscriber base and data traffic.