Re: mpls over microwave

[Bryan Fields <Bryan () bryanfields net>]

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

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