Wireless technology opens up another blue sky for video surveillance

In today's security network trend, wireless technology undoubtedly plays a role in promoting it. As for the video surveillance industry, 3G, WiFi, and WIMax are the main forces leading the video to move towards wireless surveillance. Satellite and microwave systems are also opening up new frontiers in the fields of emergency command, etc., and the emergence of the new generation 4G has made video surveillance wireless transmission enter a new era.

The driving force behind the security network trend

When you use the remote control to tune the TV channel to "CCTV5" to watch the "NBA Christmas Game", take out your mobile phone to answer winter greetings from relatives, or use your PAD to have a pleasant video chat with long-lost friends, a mysterious communication messenger - wireless technology - is diligently transmitting data through the air.

Zhang Zugang, product manager of the hard recording department of Tianjin Tiandi Weiye Digital Technology Co., Ltd., explained wireless technology: "Wireless networks include global voice and data networks that allow users to establish long-distance wireless connections, as well as infrared and radio frequency technologies that are optimized for short-distance wireless connections. They are very similar to wired networks in terms of purpose. The biggest difference lies in the transmission medium. Using wireless technology to replace wired network cables can serve as a backup for wired networks."

In recent years, the application of wireless technology has grown like spring grass. The daily application forms and potential of radio, television, mobile phones, and the Internet have been further explored. While it has brought new concepts to people's lives, it is also expanding and extending to all walks of life. The security industry, which has an ambiguous relationship with IT and communications, is naturally a major focus of wireless technology layout.

As early as the early 1980s, wireless technology has been used in the security industry. Since the WirelessLan (IEEE802.11) standard was established in 1997, wireless networks have been sought after by many security companies due to their advantages such as no wiring and strong flexibility, and corresponding wireless security products have emerged in an endless stream. Today, in the tide of security networking, wireless technology plays a role in fueling the trend - whether it is the early development of wireless monitoring and wireless alarm, which are in the limelight; or the wireless intercom and wireless access control, which are not willing to fall behind, or the smart home wireless applications that are eye-catching.

Comparison with wired

In fact, the development of wireless technology in the security industry is not "groundless". Although in terms of video surveillance, whether it is the analog dynasty of the past or the current network era, wired transmission has always dominated the entire market (to this day, its position is still unshakable), however, wired is not so perfect. In an interview, a technician from D-Link Electronic Equipment Shanghai Co., Ltd. said, "There is no doubt that wired is a very suitable method for deploying regional video surveillance networks. Even long-distance video transmission can be solved by optical fiber. But for scattered, single-point modes in remote areas, fast-moving objects, and video surveillance that needs to be temporarily deployed, wired transmission can only be out of reach. In this case, using wireless networks for video transmission becomes the only option."

We also learned from D-Link that in addition to high mobility and a range that is not limited by environmental conditions, wireless monitoring solutions have the following three advantages compared to wired monitoring:

Flexible installation and convenient networking, especially suitable for outdoor or remote applications, such as oil fields, mines, docks, construction sites, etc.

Easy to manage, maintain and save maintenance costs;

The overall cost is low and the execution efficiency is high. No need to pull wires or bury pipes, no need to destroy the original settings, and the expansion is extremely convenient.

The future development of surveillance networks will inevitably require the video surveillance industry's transmission methods to be more flexible and adaptable, and to be able to be quickly deployed and flexibly networked. Therefore, wireless will be an indispensable part of surveillance.

Luxurious wireless monitoring lineup

At present, the wireless technologies used in the field of video surveillance include satellite, microwave system, wireless mobile network, broadband wireless, etc. "Affected by factors such as the frequency band and transmission power of microwave signals, various digital wireless network transmission technologies have great differences in technical parameters such as network transmission rate and coverage. Due to cost reasons, WiFi (wireless local area network), WiMax (wireless metropolitan area network) and 3G (wireless wide area network) are currently mainly used in the field of video surveillance." Zhou Xin, product manager of Hikvision, said.

In his opinion, with the gradual commercialization of 3G, especially the large-scale development of TD-SCDMA in China, which brings relatively ideal bandwidth and network coverage, more video surveillance projects will use 3G technology. The other two wireless technologies that deserve high attention are WiFi and WiMax. With the large-scale development of wireless cities and its superior performance in some video surveillance cases, WiMax wireless video surveillance technology will have a promising future.

3G, WiFi, and WiMax lead the way

Of course, although WiFi, WiMax and 3G all share the goal of ensuring stable data transmission in the monitoring field, in their initial designs, they used different technical means to solve different application problems.

1. 3G occupies the high ground of wireless monitoring

Some people say that the advent of the 3G era marks the beginning of a new era for wireless transmission. In the security industry, 3G wireless monitoring products are also labeled as "milestone products in the monitoring field" by the industry media.

"3G networks can support transmission speeds of at least 2Mbps, 384kbps and 144kbps in indoor, outdoor and driving environments respectively, which is a qualitative improvement over the bandwidth of the currently commercially available mobile broadband networks CDMA (153.6kbps) and GPRS (115.2kbps). It can better meet the bandwidth requirements of network video surveillance and provide clearer and smoother video transmission effects." Song Huatong, manager of the wireless mobile department of Shenzhen Sanshan Technology Co., Ltd., said, "In the past, wireless network surveillance has been limited in its application scope due to bandwidth limitations, but the commercialization and popularization of 3G can better solve the bandwidth problem."

Since the beginning of 2009, driven by telecommunications operators, 3G surveillance has been heating up, with small-scale applications blooming everywhere. From the perspective of the previous year, the 3G concept has completed its warm-up exercises, and has gradually entered large-scale applications from small trials. In addition to adding new features and expanding new functions for the video surveillance services of industry users, it can also provide home surveillance services for mass users, including value-added surveillance application systems based on the 3G platform. With the gradual development of operational-level video surveillance services such as China Telecom's "Global Eye" and China Netcom's "Wide Vision", operators have also begun to consider the integration of network video surveillance and 3G as the next important business growth point. From the perspectives of technology, business and cost, the application of 3G will have a profound impact on video surveillance and even the entire security industry.

2. WiFi takes the “wireless city” express train

In fact, WiFi is widely used in the security field and is currently the most widely used wireless technology in wireless monitoring. However, it is limited by the transmission distance (the signal radius is only about 100 meters), and has been struggling in small-scale indoor monitoring.

In 2011, with the global "wireless city" construction trend, the value of WiFi in the security industry was re-evaluated. Different from the previous local government's enthusiasm, China Mobile, China Unicom, and China Telecom began to actively deploy "hotspots" in key areas such as airports, universities, and transportation hubs in cities, and combined with their own user resources to vigorously promote it. It can be seen that behind the 3G war, the three major operators' secret competition over WiFi is becoming more and more obvious.

"The main motivation for operators to promote WiFi currently comes from the pressure from data services. The development of wireless Internet has brought about a surge in data services, such as video services, which require a large amount of bandwidth." said an IT industry insider.

In this regard, Zhang Zugang of Tiandi Weiye gave a more in-depth explanation: "Although some people are still pessimistic about WiFi, whether it is 3G, TD-LTE, or the future 4G, it is absolutely impossible to support the large-scale application of wireless Internet in terms of capacity and cost. Once there are too many users, the network will be blocked. WiFi access will become the most suitable means of diverting data traffic due to its fast speed and low cost." Therefore, WiFi must be the vanguard in the construction of wireless cities.

3. WiMax may make a comeback

WiMax, proposed by the WiMax Forum and formed in June 2001, is the interface standard of IEEE802.16 Ethernet, just as WiFi is the standard of 802.11 Ethernet. It was originally positioned as a new wireless transmission method to replace the latter. As a result, WiMax has been sought after by many in the wireless industry since its launch, and has become the hottest word in the industry in recent years.

Objectively speaking, WiMax has performed well in global business development. In the United States, the European Union, Japan and other countries and regions, WiMax advocates are in full swing, but in China, it has been embarrassed and rejected - WiMax has not yet obtained the landing license from the Ministry of Industry and Information Technology.

In fact, WiMax landed in China as early as 2007, and it was really popular. First, in March, China Unicom held an appraisal and acceptance meeting for the WiMax broadband wireless access trial project; afterwards, the Ministry of Information Industry's Communications Technology Committee stated that in preparation for the Beijing Olympics, Beijing would set up and build 150 WiMax base stations by the second quarter of 2008, covering 90% of the main streets in Beijing; in the same year, China Netcom was also actively testing WiMAX. Netcom companies in Guangdong, Jiangsu, Zhejiang, Shanghai and other places have carried out WiMax pilot work, among which Guangdong Netcom's WIMax wireless broadband access project has a total of more than 600 sets, which is known as the largest WIMax project in the Asia-Pacific region. At that time, WiMax commercial trials were very popular in China's first- and second-tier cities. However, in 2008, with the gradual development of 3G services by China's three major operators, WCDMA, CDMA2000 and TD-SCDMA became increasingly popular; in the noisy communications market, WiMax was rarely mentioned.

Does WiMax really have no chance in China? The originally bleak prospects of WiMax have seen a glimmer of hope in the craze for wireless cities in China. "The currently widely used WiFi can only solve indoor coverage, while fixed WiMax (802.16D) cannot achieve high-speed Internet access on the move, which greatly reduces the vision of wireless cities that can access high-speed Internet anytime and anywhere. Mobile WiMax (802.16E) can achieve high-speed broadband access on the move," said Song Huatong of Sanshan Technology. From the current perspective, WiFi + WiMax is the best solution for wireless cities. He added: "The first generation of wireless city technology solved the Internet access needs of a small number of people in a small area, but later operators and users clearly expressed stronger needs and needed to further improve the network. In the WiFi + WiMax solution, WiFi is used for indoor coverage and hotspot coverage in areas near buildings, while the more advantageous WIMax is used for outdoor large-scale coverage. The coverage range can reach more than ten kilometers, allowing a terminal to achieve barrier-free mobile roaming from indoors to outdoors. In addition, the switching problem between WiFi and WiMax has been solved."

In addition to working together with WiFi, WiMax is also exploring alliances with TD-LTE. With the help of TD-LTE's influence in China, WiMax may be able to enter the mainstream market. Song Huatong of Sanshan Technology said: "The weak alliance will eliminate the internal friction between TDD standards. In the future development of 4G, it may not only be an opportunity for TD, but also an opportunity for WiMax."

In the monitoring industry, WiMax technology has been applied to wireless monitoring in some high-end residential areas in China. In terms of future development, WiMax is also suitable for building long-distance private networks, such as oil, petrochemical and railway systems, using it to achieve monitoring and communication along pipelines and roads.

Second Group: Satellite, Microwave

In addition to 3G, WiFi and WiMax, there are also other wireless transmission pioneers such as satellite and microwave systems in the field of wireless monitoring. Although they cannot compete with the former in terms of technical cost performance and application breadth, the application of satellite and microwave systems in some specific fields cannot be underestimated.

1. Satellite-assisted emergency system

In wireless transmission technology, satellite communication technology has a high degree of maturity and obvious advantages. It has the advantages of wide service range, powerful functions, flexible use, and is not affected by geographical environment and other external environments. However, it has made some gains in the monitoring market.

It is understood that there are currently two main ways of transmitting video signals via satellite, namely "static communication" (satellite vehicles transmit in real time at fixed points) and "dynamic communication" (satellite vehicles can perform corresponding monitoring during movement). Judging from the development situation in recent years, "dynamic communication" is more favored by professional fields, especially in public security departments. At present, provincial public security departments and some municipal public security bureaus with relatively good economic conditions are generally equipped with emergency command vehicles and individual equipment of satellite "dynamic communication" systems to provide broadband communication services. In addition, it is also widely used in traffic accident exploration vehicles, fire and armed police on-site command vehicles, and customs, oil fields, mines, water conservancy, electricity, finance, maritime affairs, and other emergency and emergency command systems. The main function is to transmit real-time images of the scene back to the command center, so that the decision-makers of the command center can feel as if they are on the scene, improve the accuracy and timeliness of decision-making, and improve work efficiency.

Of course, in the field of wireless monitoring, satellite monitoring systems have never been the focus of attention, nor have they been the development focus of security wireless monitoring manufacturers. The reason why satellite monitoring applications have stagnated is its high operating costs - the monthly rental fee ranges from several thousand yuan. In addition, the existence of coverage blind spots also greatly reduces its coverage: in mountainous areas, tunnels, and urban buildings with dense and relatively high objects, the transmission signal will be affected, and may even be interrupted.

2. Microwaves are still “non-mainstream”

In the field of monitoring, the identity of microwave systems is similar to that of satellites, and they also belong to the "non-mainstream" group. Microwave technology can be divided into analog microwave and digital microwave. The microwave technology that is currently widely used in China is digital microwave (i.e. COFDM). D-Link Electronics technicians said that the use of COFDM wireless video transmission technology has good video quality and low latency, but the transmission distance is limited. It requires more than 10 watts of transmission power to transmit to a distance of tens of kilometers, and its system capacity is small. There will be mutual interference between multiple terminals in a limited area, resulting in a rapid decline in video quality or even unusable. However, since the wireless monitoring system using analog microwave technology and COFDM technology is completely open, its security is also really worrying.

However, without considering security, it still has obvious advantages in some wireless monitoring applications. Therefore, microwave monitoring equipment has been widely used, which has also prompted most domestic security wireless monitoring manufacturers to engage in the research and development and production of microwave monitoring equipment, such as Sanshan Technology and Keweitai.

The new generation shines: 4G

Before 3G applications were even implemented, the concept of 4G was widely promoted by its supporters. Although 4G has not yet cannibalized 3G, quasi-4G (TD-LTE) is already on the track and ready to take over.

If we want to explain why WiMax cannot be used in China, the existence of TD-LTE is actually an important factor. As one of the most cutting-edge communication technologies, TD-LTE has too many Chinese stamps (including a large number of Chinese patents), and therefore has always received constant and absolute care and love from the government. Of course, my country's TD-LTE technology and its applications are also at the forefront of the world.

As early as the 2010 Shanghai World Expo, the TD-LTE mobile broadband experimental network, which was "faster, smoother and clearer" than 3G, made its debut; at the Guangzhou Asian Games of the same year, the high-definition instant shooting and transmission service based on TD-LTE pushed TD-LTE into practical application; and during the 2011 Shenzhen Universiade, the TD-LTE commercial network covered the main venues of the Universiade, such as the Universiade Center, the opening and closing ceremony venues, the media center, and the surrounding Binhai Avenue and other main roads. The high-speed data transmission service (ten times that of the existing 3G network) allows citizens to experience wireless high-definition video through various terminals such as mobile phones. In the country's "12th Five-Year Plan", TD-LTE is also regarded as a key component of the "new generation of information technology".

Although it will take some time for 4G to be used in security, many security manufacturers have already started preparing for the dowry. At present, the trend of high-definition surveillance in China is becoming more and more obvious. There is nothing to brag about with 2 million or 3 million pixels. Some manufacturers have even begun to launch 10 million pixel cameras first in the industry. Once 4G "spreads" to the surveillance industry, its "powerful" wireless information transmission speed will most likely drive the mobile surveillance industry to develop by leaps and bounds.

Are you ready for the wireless monitoring era?

Although the scars of wireless, such as instability, unreliability, and high cost, have not yet healed, in the field of monitoring, the security industry is still pursuing it with increasing enthusiasm. With the continuous expansion of bandwidth, wireless is developing "personal business" while cooperating well with wired. From the use in small areas such as office buildings and factory areas to mobile application areas such as bus monitoring, taxi monitoring, subway and high-speed rail monitoring, and then to large-scale, long-distance fixed-point monitoring applications such as forest fire prevention, remote mountainous areas, oil fields, scenic spots, electricity, water conservancy, and environmental protection, the influence of wireless monitoring is constantly expanding.

In the view of Dong Haoqing, an engineer at Shanghai Zhixun Information Technology Co., Ltd., "the development trend of wireless system integration technology in the security industry will follow the development trend of wireless transmission technology in the communications field." Dong Haoqing also said that the current market prospects of wireless communication technology in the field of civil communications have far exceeded traditional wired transmission and access, and the same situation will occur in the monitoring field. With the continuous evolution of wireless transmission technology, it is believed that in the field of civil security, the application of wireless transmission systems will become more and more common; and for industrial applications or non-civil monitoring fields that have higher requirements for information security and transmission bandwidth, wireless transmission systems will also receive more attention, and wireless access methods may be considered more in some small-scale access.

We have reason to believe that the era of wireless surveillance is slowly approaching.