Posted: Wed May 15, 2019 15:45 Post subject: Campaatible router with separte 2.4 & 5ghz antennas
The short version:
I'm looking for a dd-wrt compatible router that has separate antennas for the 5ghz and 2.4 ghz bands. my goal is to use a directional antenna for one band and an omni for the other band.
This is what I would consider an ideal solution to my situation. Using a diplexer adds considerable cost and complexity. I'm also open to other suggestions to accomplish this same goal.
The Huawei AP6510DN-AGN is a good example of of what I imagine the router looking like.
The details:
I work in automation and we regularly are setting up temporary offices in distribution centers. It is normal for us to hook a router up to a PLC out in the field, sometimes there are several panels and several PLCs that we are working with.
I'd like to be able to leave each PLC/router with it's own access point out in the field so if we are working near the panel we have wireless access to the panel/PLC. Then use the other band for client/bridge mode to connect back to the office area.
The idea being that we can still connect to each PLC from the office area even if it is a considerable distance from the PLC.
I'm using an R7000 for the temporary office presently and find it works very well using 2.4 ghz as a bridge to another router close by, and 5 ghz for everything local. It looks like the R6700 and R7000 are about the same.
My concern is that these units use 3 dual band antennas rather than separate antennas for each band. So if I start replacing an antenna or two to get directional gain on the 2.4 ghz band. It's going to negatively affect diversity and mimo on both bands.
Has anyone replaced only one of the omnidirectional antennas on a unit like this and had decent results without it affecting performance to other local devices not in the path of the directional antenna?
Joined: 04 Aug 2018 Posts: 1447 Location: Appalachian mountains, USA
Posted: Fri May 17, 2019 17:43 Post subject:
Hi fourbin... Yes, I've wondered about the same thing. I have a nice 2.4 GHz yagi but don't dare use it with my dual-band router in client mode because (and it's clear this is your concern as well) it would reflect any 5GHz transmit power presented to it by the router right back into the router. The router's wifi circuits may or may not be designed to handle that. My guess is not.
egc: This is why it is not just a question of detachable antennas.
Anyone? _________________ 2x Netgear XR500 and 3x Linksys WRT1900ACSv2 on 53544: VLANs, VAPs, NAS, station mode, OpenVPN client (AirVPN), wireguard server (AirVPN port forward) and clients (AzireVPN, AirVPN, private), 3 DNSCrypt providers via VPN.
While it is undeniable that what you are suggesting would work. It then becomes necessary to buy two pieces of hardware for each PLC in the warehouse.
It's frustrating because there are a few models out there that I'm aware of with the right hardware configuration, like the EnGenius ENS620EXT or the HP 525 802.11ac access point. I just can't seem to find anything dd-wrt compatible.
I'm actually surprised that more people aren't interested in a setup that would handle semi long distance bridges as well as local wifi access.
That's true, SurprisedItWorks. Diversity and MIMO aside, SWR issues also limit alternative antenna options.
While it is undeniable that what you are suggesting would work. It then becomes necessary to buy two pieces of hardware for each PLC in the warehouse.
Two separate routers, one in client mode and the other in AP mode with their lan ports linked? Disable the unneeded radios on each unit.
This would also allow for better placement of each unit, using whatever length ethernet cable you need between them rather than making a compromise or using long coax runs for the directional antenna which introduces signal loss
If you dont need a current wifi spec, something like the old wrt55ag had separate mini pci radios for each band and each radio had its own antenna. The antennas were not removable though, nothing a drill/dremel and some coax connectors couldn't solve. I think ddwrt runs on this.
I'm trying to stay away from more hardware. Which is why I'd rather not have to add dedicated P2P links, or adding a second router for every PLC in the warehouse, any lengthy runs of coax or ethernet would ideally be avoided. Usually you have limited access to 110v AC in these locations and a 2nd device would mean adding a powerstrip or extension cord away from the panel to power the other device. Every few months this all has to be packed up and moved across the country to a new jobsite.
All that being said. The wrt55ag looks like it might fit the bill. Bit of a shame that it has to be modified and isn't current wifi spec, but honestly, I can live with that. The mini-PCI radios are a really neat plus. That might give me the option to replace one with a 900 mhz radio for certain applicatins.
Big thanks for bringing this model to my attention.
The thread really gains traction when KD5MFW starts adding to the conversation.
It sounds like replacing one of the omnidirectional antennas with something like a yagi or parabolic dish should actually work well enough (as long as the directional antenna is dual band so that the router's radio isn't damaged by high SWR) leaving two antennas for local traffic and diversity. The link via the directional antenna will take a speed hit at longer distances because of the single antenna, but that would be the case even if the 2.5ghz/5ghz antennas were separate.
While reading about the other netgear routers in the 7000 series. I discovered that the R7500 (X4)(v2 for sure, and i think v1 also) has 4 antennas with 4x4 stream capable 5ghz, but only 3x3 on the 2.4 ghz side.
It appears that one of the antennas ports is 5ghz only. I interpret that as a great candidate for using a monoband 5ghz directional antenna without SWR issues that could otherwise potentially damage the 2.4 ghz radio.
Still not exactly what I hoped to find, but it might fit somebody else's niche application.
Thanks to all who took the time to read and contribute to the thread. I'll quit adding to it and let the thread die.
Posted: Sun Jun 09, 2019 22:12 Post subject: Campatible router with separte 2.4 & 5ghz antennas
I wanted to come back and add these routers as the closest thing I have found. For most purposes, these are almost exactly what I was looking for,
"Tri-Band" routers have half of their antennas dedicated to either the upper or lower half of the 5GHz band, the other half of the antennas are connected to the 2.4Ghz radio and to the radio the covers the complimentary side of the 5Ghz band.
So, you could take a router like the Asus RT-AC3200, leave the three dual band antennas alone, which would give you dual band (2.4GHz & 5GHz Low) connectivity to all of your local devices. Then remove the other three antennas that are dedicated to upper portion of the 5GHz band, and replace them with something like an L-Com HG4958-17DP-3NF or similar antenna to use for a long distance link.
Alternatively, you could disable the 5GHz Low radio, then use the 2.4 Ghz radio for the long range link, leaving the 5GHz High radio for local traffic.
The four routers that I have found that are DD-WRT compatible, have removable antennas, and are "Tri-Band":