Huawei Wireless Solution Improves Rail Services

Background

Shenzhen’s Metro Line 11 started operations on June 28, 2016. Line 11 is also the first rail express with a peak speed of 120 km/h, which is significantly higher than the previous five lines’ top speeds of 80 km/h. As an express line, Line 11 has a longer average inter-station distance of 2.8 kilometers than previous lines in Shenzhen. It takes 30 minutes to travel from Futian to Shenzhen Bao’an International Airport, and 1 hour to the boundary between Shenzhen and Dongguan. Currently, Line 11 is an unsurpassed city rail link in terms of length with unique construction, investment volume, and design peak speed in China. There are four elevated stations and five elevated rail segments along Line 11.

Challenges

Shenzhen Metro Line 11 is a typical express line with a peak speed of 120 km/h and a total of 18 stations covering over 50 kilometers. This line functions as both the airport express and the intercity metro line. In addition, Line 11 covers diverse terrains such as elevated roads, tunnels, and flat ground. Traversing to Shenzhen Bao’an International Airport, Line 11 experiences complex electromagnetic conditions. This causes strict demands on the train-to-ground wireless network in terms of mobility, reliability, and anti-interference capability. The metro train-to-ground wireless network provides large-bandwidth services such as onboard video security, passenger information delivery, and advertisement pushes. It is an important metro subsystem to provide value-added services and improve passenger experiences.

Wireless Local Area Network (WLAN) technologies are universally applied to traditional train-to-ground wireless network solutions. However, the Communication-Based Train Control (CBTC) system uses WLAN technologies to operate on the public frequency band of 2.4 GHz with insufficient available frequencies. This makes it extremely complicated to plan, design, and deploy WLANs. Metro lines using traditional solutions have numerous track-side Access Points (APs), which cause high transmit power and dense interference. Additionally, the prevalence of operators’ 3G and 4G networks exponentially increases the number of mobile phone Wi-Fi hot spots. This deteriorates the operating environment for WLANs and affects the operational safety and efficiency of metro trains.

Solution

To resolve the challenges for Shenzhen Metro Line 11, Huawei offers the eLTE train-to-ground Wireless Communications Solution with the following features:

• Seamless coverage: This solution utilizes coverage enhancement technology specific for metro line applications. The number of track-side devices deployed is one fifth of that deployed with traditional solutions. This solution applies multiple coverage techniques including leaky cables, antennas, and indoor distribution. This ensures seamless coverage under environment conditions such as tunnels, elevated roads, and rolling stock depots.
• Anti-interference: Huawei’s eLTE solution has its unique Automatic Frequency Control (AFC) technology to ensure stable data transmission at a high train speeds of 120 km/h. Wireless anti-interference technologies work with engineering deployment schemes to effectively avoid interference. The success of Line 11 is due to the feasibility of LTE technologies in express line applications.
• High bandwidth: While meeting the requirements for high-speed train travels, the eLTE solution helps Shenzhen Metro Line 11 implement real-time data transmissions. With this solution, Line 11 can deliver news, games, and other real-time video services, as well as uploading security videos in metro carriages and coaches in real-time.

Moreover, during the construction of Shenzhen Metro Line 11, implementation of the LTE train-to-ground wireless solution encountered complex environments, tight delivery schedule, and other difficulties. With extensive delivery experience in the railway industry and supportive delivery team, Huawei provides Shenzhen metro with end-to-end LTE solutions.

• Precise planning: Network estimates, system simulation, design examination, parameter definition, and system design are appropriately planned based on railway requirements for wireless coverage. In this way, Huawei ensures the network planning is precise, reasonable, and scalable.
• Reliable implementation: The solution implementation in metro scenarios encounters various difficulties such as complex environment, unmanageable quality and tight schedule. To cope with the difficulties, Huawei provides professional, efficient, and reliable services in terms of solution test, system configuration, commissioning, and static acceptance. Huawei offers experienced industry experts and pioneering project management to effectively identify and control project risks, as well as responsive Research and Development (R&D) teams to support quick troubleshooting.
• Specialized network optimization: Metro operations feature high security requirements, complex coverage scenarios, difficult coverage control, and unknown interference sources which requires network performance optimization. Huawei provides integrated solutions with dedicated network optimization services such as single-site verification, entire network optimization, voice service optimization, data service optimization, and system verification.

Benefits

By the end of June 2016, with the eLTE Urban Rail Transit Solution, Huawei has successfully won the bids for 14 metro lines in 10 cities, including 3 lines carrying CBTC. The solution occupies over 60 percent of the market share. In 2013, Huawei’s eLTE Urban Rail Transit Solution was implemented on the Zhengzhou Metro Line 1, which is the world’s first LTE metro network providing train-to-ground mobile broadband services. Huawei’s eLTE solution is now successfully operating for the Shenzhen metro. 

With rapid growing urban rail transit and continuously emerging high-speed lines around the world, Huawei will further optimize its rail transit solutions. By working with industry partners, Huawei intends to develop increasingly solid and reliable train-to-ground wireless solutions for rail transit systems to enhance overall rail transit operational capabilities. The systems include CBTC, Passenger Information System (PIS), and Closed-Circuit Television (CCTV) for multiple transit methods such as metro, light rail, tram, and inter-city express.