Member Discussion

200 Camera Non Line Of Sight Wireless Network Design

We are planning to monitor a small district of about 200,000 m2 using a wireless network, IP 2MP IR cameras and VMS from Milestone.

The big challenge, beside the limited budget and the impossibility to carry out digging in the streets, is the design and implementation for the wireless network, as there are many small buildings, streets and narrow sidewalks. Most of the professional companies I know refused working on the project as their systems are based on LOS concept.

The no of cameras suggested to cover the area is 200 of 2MP each, thus big bandwidth is needed.

Any idea about a professional company that can implement that wireless network:

Either as NLOS, or using WiMax or using WiFi

Sounds like a disaster waiting to happen :(

Have you inquired with the local mobile / cellular carrier? Those networks are built to be non LoS, are licensed, etc. Bandwidth capacity may be an issue but I'd check with them.

Another potential hack is to set up lots of small ptmp networks with a handful of cameras and then connect them into local wired networks (cable / telephony / etc.).

Try mesh network, with omnidirectioal antenna. We have implemented NLOS CCTV Surveillance with Tropos Networks. From my experience CCTV with wireless is like playing with fire. Issue with mesh network is packet loss when the wireless node switches from one channel to another.

I am in the process of doing something similar, although my bandwidth requirements are not as great. I am using a Proxim Quickbridge setup (point-to-point) to join 2 halves of a large housing community. It will support up to 300Mbps and can use the upper 5GHz band (channel 149 and up) without licensing. I've used the Proxim point-to-multipoint setup as well with excellent results.

Your other option would be to consider using a camera system that has true edge recording capabiltity to SD card. This would eliminate most of your bandwidth requirements and result in almost no loss of video. What you are looking for in a video sysem is just that, Video when you need it. Wireless is like playing with fire as mentioned and recording centrally to a VMS has many drawbacks in such a system- the most troublesome being loss of video and true reliability, not to mention being very expensive.

At least with edge recording you will still have video should your Wireless network go down.

Or as mentioned create multiple PtMP networks but you will still run into reliability and high cost issues.

I second A's suggestion. Even if you have plenty of bandwidth, given the increased risks of temporary outages on wireless systems, using SD cards for storage is a good idea.


this is Cosimo from Fluidmesh. Doing wireless video surveillance at 2.4/5 GHz without LOS is a bit like playing Russina Roulette as it is impossible to predict how your network is going to perform unless you install it. Have you considered taking a 'divide and conquer' approach where you split the system in a combination of PTP, small PTMP and linear mesh along the streets? Depending on the budget that you have and on the layout of you area, you may be able to pull it off. Actually having buildings and narrow streets could help you in avoiding co-location interferences in your network and allowing you to reuse more channels. It is really hard to make too many suggestions without looking at a map. If it could be of interest to you, I will be glad to give a look at your system and give you some feedback.



I agree with Cosimo, small PtMP set up.... linking to a P-P high throughput "highway" via data switch....

The equipment we carry now has a throughput of 800Mbps making it ideal for this type of set up......

Just need to ensure the data switch also has through-put capacity...