This seems like something that should be easy to find, that should be listed with the products, but isn't. What antennas work well with the 2.4 GHz PMP 450 connectorized SM? I need serious gain to blast through the woods, and I'm willing to pay for a better radio if it does the job. The integrated unit is a joke -- I'm sure a cheap brand U radio with its built-in 20 dB dish, or ePMP with Force 200, would outperform it just on the basis of antenna gain. But I want maximum performance in the woods. I see a lot of single-pol panels, probably left over from way back when, but not a ton of dual-pol panels or even SM-sized dishes. Is there a good 18-20 dB panel or 15-18" dish (I want to reserve the big RD24-style antennas for when they're really needed) that anyone would recommend for the 450 family SM? Thanks...
Have you checked out the new PMP450i 900MHz radios? If you're goal is to get through trees, I would start there. If that isn't an option, and you want maximum performance, I'd try using a 2' dish... unfortunatly, there's no OEM option for this, and very few 3rd party options. One of the best 3rd party options would be to use Ubiquiti AF-2G24-S45
2.4GHz airFiber Dish, 24dBi, dual-Slant 45. You'll need to use some RF adapters to convert from RP-SMA to N (IIRC, please double check the correct adapter before you buy!!), but this not only gives you 24dBi gain, it also gives you dual-slant polarity which will match the polarity of the OEM antenna if you used that on the AP side. Dual-slant will give you a little bit of additional performance... all for a price point just south of $250. You could go with a Radio Waves dish, or Andrews or something carrier/cellular grade like that... but it will cost just south of $1000 and will weigh a ton.
Maybe this isn’t what you’re looking for, but we’ve had ok results with Lanbowan.
http://www.lanbowan.com/ANT2327D19C-DP.htm
http://www.lanbowan.com/ANT2327D19S-DP.htm
http://www.lanbowan.com/ANT2327D22PG-DP.htm
http://www.lanbowan.com/ANT2327D24P-DP.htm
The Lanbowan antennas are interesting -- their specs are exactly what I'm looking for (especially the panel and the solid dish -- grids do NOT work in ice territory). But it's an unknown Chinese vendor with no obvious US distribution. This might not fly with the network owners (US state government). Also there's no price listed, but I suspect it's very reasonable.
Eric, I'm asking very precise questions for a reason, and this is not about 900 MHz. The point of 2.4 GHz is to avoid needing to put as many users on TVWS, which blasts through trees even better than 900. I'm trying to determine if PMP 450 is worth using on 2.4, vs. sticking to plain old Ubiquiti (no sync, ugh) or ePMP. Every dB counts, and I'm not sure how many dB I gain by using the superior PMP 450 radios. The target area I'm looking at is essentially the northern Appalachians, steep New England woodland. We have some Ubiquiti 2.4 working in a trial, but not on the hardest paths, and it does bog down (no surprise) shooting straight through a spruce forest, though it does a lot better than 5 GHz in such cases.
The Ubiquiti slant-pol dishes are nice but I wish they had a smaller one for the less-difficult paths. There's a huge gap between the 2' dish and the PMP integrated panelette.
Hence I'm still open to other suggestions.
@fgoldstein wrote:
The Ubiquiti slant-pol dishes are nice but I wish they had a smaller one for the less-difficult paths. There's a huge gap between the 2' dish and the PMP integrated panelette.
Hence I'm still open to other suggestions.
For short shots use integrated, for medium shots use integrated + reflector dish, for long shots or thick non-LOS, use a 2' dish. As far as TX power is concerned, maximum that the PMP450 will put out is 22dBm. Maximum for ePMP (depending on region) is 30dBm. All things considered, you're probably better off using ePMP for this application as you have a low cost integrated unit for short shots, a 1.5' dish for medium shots, and you can easily use a connectorized ePMP radio without having to use adapters with a 2' ubiquiti dish.
I really don't want to use reflectors. They don't have a good reputation for performance, and strike me as risky in heavy snow and ice.
Transmitter power doesn't really matter -- the FCC limits legal power on 2.4 GHz is based on antnena gain (2 for 3 rule), so 22 dB with a 20 dB dish is near the limit for clients anyway, and +36 is always the EIRP limit for APs, which means +22 with a 14 dB sector is the legal maximum. Not that I haven't seen WISPs exceed it, but I need to be careful here. It's the download (AP transmitting) side that matters most anyway in the consumer application. (The opposite applies to the camera application, but that's all 5 GHz urban.)
ePMP certainly is more attractive on price, but what about performance differences? A number of WISPs have sworn by PMP450, and since i haven't done a comparison test, I don't know what it really means. I think the major difference is a lower baud rate in PMP (with more OFDM carriers), resulting in both a sharper channel edge and a much wider time window for in-phase arrival of reflected signals. And probably more DSP horsepower. Since ePMP and UBNT both use Atheros chips, the main difference is probably in the availability of sync (no small deal).
Here are some reasons to go with ePMP over PMP450:
- Lower cost AP's and SM's
- More SM options then 450
- No SM license/bw restrictions
- Higher raw throughput at the SM in certain situations
- GPS sync if you need it, if you don't, then just buy regular radios and save even more $$
- Higher power output
We use ePMP for smaller micro-pop's or repeater sites. We use PMP450 for large tower farms, where's there's lots of interference and harsh winter/summer conditions. PMP450 (arguably) deals with interference better then ePMP.