i'll open with, both systems work great when dealing with trees, they both run circles around the PMP100 in that regard. I've got far more experience with the EPMP line as that was our product of choice.
build quality, we've only had a few EPMP radios die of several hundreds... none of the defects, 1 direct lightning strike, 2 from customers messing with stuff and 1 from the wrong PS attached, the CPEs don't do well on 48v lol
over subscribing, thats always tough. the 450 has tighter frame control than the EPMP, and it doesn't build latency as fast. you'll be able to over subsribe more, but thats a case by case thing. we've got EPMP aps with 40 people and its moving ten meg at night, they just don't use it. and we've got APs with 40 people on it pushing 80 to 100 meg at night.
its hard to mark one as better than the other, as they both have their unique pluses. the EPMP is low cost, great performance for the $$$
in a technical comparison, the 450 will win hands down.
the 450: latency doesn't build with attached subs nearly as fast. the MAC layer is in the same foundation as the old PMP 100, just improved.
the 450 can re-use frequencies faster. the EPMP does snyc, but you've got to watch the density of APs. you'll have to designate front and back APs, and you must maintain that pattern correctly or you'll degrade AP uplink performance. the PMP 450 is less susceptible to that in dense situations (it can get uplink issues from neighing APs like the EMP can, its just more resilient to it.) with the EPMP, if two APs that are both marked as "front" on the same channel and they hear each other within the needed SNR range of the CPES that are uplinking, they will self cause problems with each other. proper sector tilt and re-use planning can prevent that. the 450 doesn't have that issue.
the 450 can connect 200 CPEs per AP, epmp 120 max. the latency penalty can be pretty big at that point for the EPMP. as much as 100 MS the 450 doesn't have that penalty.
the 450 codes to qam256. the epmp codes to qam 64.
the EPMP has more code steps, which can be helpful sometimes.
the 450 has lower SNR requirements per modulation steps.
if memory serves me, the PMP 450 use 1024 sub carriers, which is very helpful in dealing with noise, physical obstructions, and MAC control. i don't know about epmp in that regard.
the 450, I would guess it to run 20 to 30% faster across the board as RSSI falls and it will keep it together
handy extras for the EPMP: you can make them hot spots at the touch of a button for events, customers who need a crazy powerful AP.
if cost doesn't matter, get the 450. if budget is a hot item, and the EPMP fits your technology needs, it is great too. the PMP 450 just does everything better. except it can't be turned into a wifi hotsop, you'll have to plug one in.
we selected the EPMP because we generally never loaded APs with more than 40 to 50 subs,
we have wild terrain to deal with and more, lower speed APs suite better for our deployment to get to the no one left behind model.
when we made the switch the ePMP, we didnt' charge our customers a dime for the changes, which made low cost appealing.
our current deployment was mostly 900 mhz PMP100, and to our suprise, we have been able to move a lot of those subs to the EPMP radios, (-60 and better cleints or clients within a mile) all moved over well.
our sites that are LOS to each other are far apart the 2 fronts and 2 backs wasn't a problem, and we complimented the 2.4 deployment with 5ghz to pickup the capacity and keep sub density down.
the EPMP line rocks! the 450 just rocks a bit more though !