Relay Server (Broadcasting Server)
กแ Function of Relay Server
The fuction of the relay server is to receive a video/audio from one source and then to transmit (or broadcast) the video/audio to many clients in real time.
กแ Requirements and Background for Relay Server
There are many requirements to broadcast real time video/audio from network cameras, network A/V servers, network DVRs, NVRs, access control systems, home servers, etc. to the multiple clients such as PC, PDA, mobile phones, TVs, network A/V servers, network monitors, etc. The relay server is mainly used because of the following reasions.
- To increase the concurrent users of a network device such as network cameras, network A/V servers, network DVRs, NVRs, access control systems, home servers, etc.
- To reduce the internet bandwidth required to stream a video/audio data to multiple clients such as PCs, network A/V clients, network video recorders, licence plate recognition systems).
กแ Case 1 : Relay Server in the Illegal Parking Detection System
The relay server (realtime broadcasting server) can be used in the illegal parking detection system to reduce the network traffic and the cost of the leased internet line between the PTZ camera on the road and the central monitoring center.
- With a relay server
The following system diagram shows the effectiveness of the relay server. With the relay server, there is only one video stream from the PTZ camera on the roadto to the PIMA server the central monitoring center. The PIMA server distributes the video from the PTZ camera to network A/V clients, PCs, license number plate recognition system, etc.
- Without a relay server
Without the PIMA server as the relay server, there are four video streams from the PTZ camera on the road to four clients (Operator PC, NVR, network video clients and license number plate recognition system) in the central monitoring center . This means that the central monitoring center should lease more broad internet line with much higher cost.
กแ Case 2 : Relay Server at the Home Network System of a Apartment Complex
The relay server (realtime broadcasting server) can be used at the home network system of a apartment complex so that hundreds of concurrent users using home servers at homes can access and see the live video from the cameras installed in the parking lots and in the children's playgrounds. That is, the relay server is used to increase the number of concurrent users accessing to the network A/V servers.
Without the relay server, it is impossible that hundreds of concurrent users using home servers at homes can access and see the live video from the cameras installed in the parking lots and in the children's playgrounds because the maxium concurrent users of all the network A/V servers available in the market are less than one hundred.
กแ Case 3 : Relay Server at the Internet Broadcasting of Worship and Preaching at the Church
The relay server (realtime broadcasting server) can be used at the internet broadcasting of worship and preaching at the church so that a missionary far away from the church can participate in the worship remotely via the internet. In this case, several problems may occurs. In most of churches, the upload bandwidth of internet is narrow. If there are several concurrent participants in the worship via the internet, the video/audio stream is not smooth. In this case, the relay server can be installed in the IDC and the video/audio of worship and preaching can be transmitted to the relay server in the IDC and then the participants access to the relay server.
Without the relay server, it is impossible that hundreds of participants in worship can concurrently access and watch the smooth live video from the cameras installed in the church because the upload bandwith of the internet in the church is narrow.
กแ Reference Site of Relay Server
- Gangnam-gu (District) Office in Seoul, Korea
The relay server has been installed in Gangnam-gu (District) Office. In Gangnam-gu, there are Convention and Exhibition Center (COEX), World Trade Center Seoul (WTC Seoul) and Seoul Trade Exhibition Center (SETEC). The richest korean people live in Gangnam-gu.
All the cameras used to detect illegal parking on the street and the road of Gangnam-gu are MPEG4 encoded using CryptoTelecom's network A/V servers and transmitted to the relay server at the Gangnam-gu (District) Office. Then the relay server distributes all the videos from the camera via network A/V servers to the clients such as network A/V clients, operator's PC, license number plate recognition systems and network video recorders through the LAN. The relay server, network A/V clients, operator's PC, license number plate recognition systems and network video recorders were installed in the same place. So, the bandwidth of the LAN is enough and there is no need to lease the internet line. Like this, Gangnam-gu reduced the traffic from the camea on the street to many clients such as network A/V clients, operator's PC, license number plate recognition systems and network video recorders in virtue of the relay server in the Gangnam-gu (District) Office, resulting in reducing the cost of the leased internet line needed to transmit the video from a camera on the street to many clients such as network A/V clients, operator's PC, license number plate recognition systems and network video recorders using the relay server.
The followings are the photos of the central monitoring center of Gangnam-gu (District) Office in Seoul, Korea.
- Apartment Complex, Korea
The relay server has been installed in many apartment complex. The followings are some of them.
- Apartment complex at Geojedo constructed by Shinwoo
- Apartment complex at Namyangju constructed by Dongbu
- Apartment complex at Daegu constructed by Taewang
- Apartment complex at Pohang constructed by Taewang
- Apartment complex at Pohang constructed by Daekyo
- Apartment complex at Sangindong, Daegu constructed by Shinil
- Apartment complex at Shinseodong, Daegu constructed by Shinil
- Apartment complex at Jecheon constructed by Saerom
- Apartment complex at Incheon constructed by Shinil
- Apartment complex at Chucheon constructed by Daewoo
- Apartment complex at Gunsan constructed by Saehan
- Apartment complex at Sangam constructed by Daewoo