Caltta Reveals the PMR Communication Technologies Behind the Beijing 2022 Winter Olympics

The striving China once again ignited the flame of passion and dream, and the Beijing 2022 Winter Olympics, which the world has been eagerly awaiting, opened on February 4th. The "High Technology " is one of the main features of the Beijing 2022 Winter Olympics and Paralympics.

The PMR (Private Mobile Radio) system, as an important method for collaborative operation and emergency communication among various departments of the Winter Olympics Organizing Committee, plays an important role in the guarantee of the event. Caltta sent a professional support team to go through rounds of all-elements and full-process drills, and has now entered the formal guarantee phase. Then, what communication technologies are used in the support of this world-renowned ice and snow event?

“2+4” Broadband and Narrowband Convergent Solution, Inter-provincial Interconnection

There are three competition zones for the Beijing 2022 Winter Olympics, including Beijing, Zhangjiakou and Yanqing. Among them, Beijing competition zone uses LTE broadband trunking network which is working in 3GPP Band45, and Zhangjiakou competition zone uses the PDT/DMR system.

In order to ensure the unified command, coordination and emergency response of the Beijing 2022 Winter Olympics, the LTE broadband trunking network in Beijing and the PDT/DMR narrowband trunking network in Zhangjiakou have been interconnected. Through broadband and narrowband hybrid grouping, private call, group call, short message, dynamic regrouping, emergency call, positioning, and other services, it can meet the requirements of unified user and security management, operation and maintenance, command and dispatch during the formal competition.

This kind of “2+4" broadband and narrowband convergent solution that connects directly across different networks can well meet the interworking between competition zones in Beijing and Zhangjiakou, and greatly improve the efficiency of command and dispatch and the level of intelligent management. It has set a benchmark in the guarantee of major international competitions.

Broadband and Narrowband Interconnection

Smart Operation, Visualized Dispatch

In the MOC main operation center of the Beijing 2022 Winter Olympics, you can see the real-time location of each group member on the map, and you can also retrieve the mobile videos from the radios of one or more group members in real time. Units can form different groups to communicate independently or jointly across departments.

Voice, SMS, positioning, video, data and other information are available, covering every corner of event zones, ski tracks, airport high-speed rail and highways. A panoramic view and one-click command can be provided on the command center and dispatch console, providing secure and efficient communication guarantee and visualized dispatch for the Winter Olympics.

Dual Backup, High Reliability

In order to ensure the reliable operation of the system, a variety of backup methods are adopted, including dual backup of transmission links, dual backup of remote disaster recovery, and dual backup of physical devices of core switching units. The two sets of system are mutually main and standby. When the main system equipment has a catastrophic failure or breakdown, it can be automatically switched to the standby node in different place to quickly restore the services.

At the same time, the physical device of the core nodes is double-backed up, so that when a single node fails or is physically damaged, services can still be carried out smoothly without interruption.

High Reliability of Main and Standby Core Networks

Push to Talk Instantly without Losing the First Word

The referees of the Beijing 2022 Winter Olympics have extremely high requirements for the response of the system. The Beijing 2022 Winter Olympics Organizing Committee clearly stated in the requirements: the delay of establishing a private call is ≤300ms, the delay of establishing a group call is ≤300ms, and the delay of applying for the floor is ≤300ms, which must achieve the effect of "push to talk instantly without losing the first word". Therefore, time-consuming analysis was carried out segment by segment for the duration of narrowband trunking group call connection, including the narrowband radio PH790 sending the call initiation message, the system issuing the channel assignment message, the uplink voice header from radio, downlink voice header delivered by the system, etc.

The process optimization was carried out for each segment. After repeated optimizations and tests, the end-to-end delay of the media plane finally reached within 260ms, and the voice was clear without losing any word, and successfully passed the test of the International Snow Federation.

Low-temperature Resistant Battery, Long Battery Life

The average outdoor temperature in the Zhangjiakou competition zone is -20°C, and even reaches -30°C. In order to guarantee the stable work in the outdoor low-temperature environment, the narrowband radio PH790 has been optimized in terms of cold resistance with improved power mode, professional low-temperature resistant battery and. reduced shutdown threshold at low temperature, passing the evaluation and certification of the authoritative organization. The battery life at a low temperature of -33 ℃ (the ratio of transmit:receive:standby is 1:1:8) is 8.5 hours.

Serving the Beijing 2022 Winter Olympics is not only an honor but also a responsibility. Caltta keeps innovating, and facilitates the Olympics with high technology, to ensure an orderly and efficient ice and snow event.