Call for Customers Deploying with Frequency Re-Use

I would love to hear from anybody that's deploying PMP 450 using either 60 or 90 degree sectors, and employing the ability for the system to re-use frequencies, either in ABAB or ABCABC fashion.

Please post as much detail as you can if you're doing this, screenshots of the radios, and pictures of the base station site if possible.  This is a great place to show off your high capacity installations, and help fellow customers to do the same.

If anyone has any questions on this type of deployment scenario, this would be a great place to ask as well.

Thanks in advance!


We've deployed over a dozen PMP450 3.65 AP's in ABAB configurations using both Cambium's 90 degree sectors (which is actually a 60deg) or using dual-band, 65deg 2.4/3.65 sectors (both PMP450 2.4 and PMP450 3.65 AP's connected to a single antenna). We try to use 20MHz channel widths for 3.65 whenever possible in ABAB configurations. At one site we have (5) 3.65 sectors, and we were able to put enough separation on the 5th sector to use a 20MHz channel width @ 3675 without it causing issues with the ABAB sectors at 3660 and 3690. We've also found that using high quality antennas with excellent front to back rejection characteristics, along with electrical down-tilt on the sector can help improve performance even further.

Overall we're very happy with Cambium's GPS sync and frequency re-use features. It's allowed us to more then double our capacity at every site we've deployed on, due to frequency re-use and the removal of guard bands.


That's the first I've heard of using a single antenna for both 2.4 and 3.6.  How did you connect both APs to the single antenna?

Pretty simple actually, it's just two antennas in one enclosure, it has 4 ports on it. Cel carriers use them all the time because they typically operate on multiple bands. It costs less then buying two separate antennas, and you only pay for one antenna collocation.


That sounds amazing.  Do you know the brand or manufacturer?  I'd like to pass that along to the boss.

Have a great weekend!

I sent you a private message with a link to the company and the antenna. You can see if you have new mail by looking at the envelope next to your name in the upper right hand corner of the forum pane.

In any case, we've been ordering this antenna from Alpha Wireless for 2.4 and 3.65 use. Be warned, it's not a small antenna, but if you're used to working with Cambium's PMP450 2.4 dual slant antenna, then the size shouldn't be too surprising. When you order it, make sure you specify that you want 'N' female RF connectors, otherwise they'll send you the default, which is 7/16DIN connector that cellular operators like, and then you'll have to use adapters.

There are a couple other manufacturers that make dual/multi-band antennas (ITElite comes to mind), but the Alpha antennas, while being expensive and more difficult to get, are some of the best made antennas in the world, and they produce antennas for various cel phone companies world wide. Also make sure to take note when looking for compatible antennas to keep in mind that both the ePMP and PMP450 flavors at 2.4GHz, both utilize dual-slant i.e. +-45deg polarization.


I only have one pair of APs back to back using the same frequency, and it seems to be working well.

One of my concerns with 90 degree antennae is the possibility of having a culster of 4 APs at NE/SE/SW/NW, and having customers directly North and South aiming directly at each other on the same frequency.  We don't have enough SMs on yet to know if that will be an issue, but it's something to consider.