Project Description
In order to alleviate the persistent ailment of urban traffic congestion, the method of combining roads with bridges was adopted in 2016, to vigorously build urban expressway, and initially form an expressway network that covers the whole city. Various intelligent transportation modules including traffic monitoring subsystem, HD speed trap subsystem and illegal capture subsystem are added for the construction of expressways in Hohhot City, in order to better use and maintain expressways. Collection of images and videos of expressways is required for these modules, which shall be transferred to the command and monitoring center.
System Requirements
1. Network bandwidth requirements: 100M connection is set up between speed trap communication device and site video capture device, gigabit link is set up to connect rendezvous point uplink of speed trap and transmission link of China Netcom operator, and 10 gigabit link bandwidth is set up for access of China Netcom operator to the core computer room of expressway through a special circuit converged by multiple links.
2. During design of network scheme, it shall simplify communication devices as far as possible, decrease failure risk points, and reserve extra device interfaces, in order to adapt to business expansion in the future.
3. Data delay of network transmission is definitely specified to guarantee the real-time data transmission of various subsystems of expressways in Hohhot City: upper limit of network delay is 300ms, and upper limit of delay variation is 50ms.
Solution
The scheme of networking with IS2000-2412 network industrial switch and IS1000-1108 non network industrial switch recommended by Primestone Network can synchronously solve the problems of image and video traffic transmission in the traffic monitoring subsystem, HD speed trap subsystem and illegal capture subsystem. This scheme has the outstanding features below:
1. Optical interface is directly provided in the industrial switch to replace the traditional networking mode of combination of industrial switch and fiber optical transceiver, decrease failure risk points, and improve efficiency of networking.
2. Combination of network and non network industrial switches is a cost-effective networking scheme, which can not only control cost of networking, but also provide the convenience of management and maintenance, in order to quickly localize and solve problems.
Topological Structure Diagram
The communication network on site is divided into three layers, including access layer, transmission layer and kernel layer from bottom to top.
Access layer
The on-site devices including speed trap signal machine, HD IP network monitoring camera, E-police capture camera, etc. are accessed to the industrial Ethernet switch of the nearest speed trap IS1108 through 100M network interface.
Transmission layer
The transmission layer constructed through the network of local China Netcom operator of Hohhot City shall be rented by system users for years.
Kernel layer
Managed by the established detachment center LAN, it will finally achieve the exchange of all information.
Why should the Primestone Network be selected?
High redundancy and high reliability
For ERPS ring network design, self healing time of ring network is less than or equal to 20ms. Meanwhile, redundant double power access design adopted for the devices in this scheme not only increases the reliability of power supply during equipment operation, but also improves network redundancy above convergence layer.
Low time delay and low cost
All switching devices of Primestone Network are less than 10us upon test, time delay and dither of China Telecommunication Technology Labs. Operator network is rented as the transmission network, to save the costs for setting up long-distance optical cables and post-maintenance. Meanwhile, speed trap communication device IS1108 without management function is used to save the costs for management and exchange software.