On 2/6/15 11:32 AM, Donn Lasher wrote: > Properly engineered, however, is the key. Make sure whom-ever is building > your links looks at vendor specs, builds a real link budget (including > losses from connectors, cable, grounding, etc) properly weather seals > everything, and try to get at least a a 20db fade margin if you can. If > the things I just mentioned are confusing to your RF guy, you might want > to get outside help.
Make sure they can know the models for propagation as well. At lower bands fading caused by K factor change can be a bitch and is the predominant mode of fading. on the higher bands (>11GHz) rain fade is the predominant mode of fading. If you want your network to have 99.999% uptime, the links need to be engineered for 99.9999% uptime. Make sure the consultant knows Pathloss5 and is not using a vendor's program for that (orthogon/motorola/cambium/whatever they call them now) loves to push their own shitty program. If you're using a dynamic data rate radio (most are), ensure you engineer for highest data rate you need. If you run the calcs and it shows 99.9999999% at bfsk but you need 128qam to get your full data rate, what good is it? congestion do to link down modulation is still an outage. -- Bryan Fields 727-409-1194 - Voice 727-214-2508 - Fax http://bryanfields.net