WIFI Stability

[cholmes28]

I am using the Asus RT-N66u with a Cisco modem, on a Comcast 50Mbps Internet connection. I have the router on the 2nd floor on one end of the house, and the distance to the other end is about 50'. All I have to do is walk down the staircase, and about 25' to the middle of the house, and my wifi signal drops. So I bought an Amped Wireless 1000mh external antenna which now enables me to get a consistent 2 of 3 bars on an iPhone 4s, and 4 of 5 bars on an apple TV. However, I am having an issue where random clients just lose their wifi signal completely. Then I go back to the connection manager, see the network which shows great signal, hit connect. Sometimes it connects just fine, other times it will say "Unable to join xxx network". If I reboot router, it usually works, or I just have to wait a bit, and suddenly it connects again.

Prior to this setup, I had U-Verse Internet with ATT's 2Wire router, and it worked perfectly, but I moved and had to switch to Comcast.

I am in range of about 10 or more AP's, but regardless of what channel I select, they all seem to be present. I have tried channels 1, 6, 11, and it does not change the number of AP's, nor does it help with my issue. I finally had to run an ethernet cable from router to Apple TV just so I could stream a movie without losing connectivity multiple times in middle of a movie. Any suggestions would be great.

 

[stevech]

WiFi client software report SSIDs detected on a survey-scan of all channels. The list will vary over time.

Your choice of channel is independent of the above survey.

Regarding the amp'd WiFi. that helps the TO-CLIENT, but does not do much for the FROM-CLIENT signal.

The distances you speak of sound reasonable. If the client is reporting a very good signal FROM the router, then the router should have nearly as good a signal FROM the client. If the router or amp'd AP has very much more power than the client's transmitter, you'll have an unbalanced link. That means I can hear you but you can't hear me ("I" being the client).

DUe to the short distances, I think you have something else going on, such as the clients have a list of PREFERRED SSIDs and they try to switch to a neighbor's SSID. No doubt, your systems' SSID is not generic, right?

 

[tipstir]

First off is this house ground level or do you have another floors?
From where you have the main router also wireless AP the signal should be -20 to-30dBm are you getting those numbers in a WiFi Survey?

Take a laptop running WiFi analyzer if you have android tablet download WiFi analyzer app scan your house for WiFi and dead spots.
Also should have stick with the same brand you have for your main router to extend the WiFi.
These WiFi Router with 256MB of RAM, Higher NPU of 600MHz or higher tend to work more ideal with WiFI HD 1080p Streaming than those that only support stronger Mw WiFi.
That AppleTV mini cube should be apple to play 1080p via WiFi if it doesn't then the hardware using for WiFi can't support higher streams media.

Do you have managed switch in your network layout. Are you just running patch cables into the main router?

 

[cholmes28]

Comcast cable goes into modem, then out to router. From router I have one cat5e to an inexpensive switch (non-managed), then patch cables from switch to several devices in same room as router. Router is on 2nd floor of a 2 story house. The house is 50' from one end to the other. Then I have a 125' cat5e running from router up into attic, down outside of house on opposite side, and into another non managed switch, then patch cables to an AV receiver and an Apple TV. All wired clients work great, and speed is as expected with my 50Mbps broadband. The issue is that the wireless clients lose connectivity to the router all the time. These clients are various iPhones (4s & 5), and one Win7 laptop. I also have a Macbook Pro, but it never loses connectivity. As far as the iPhones, when they can't connect, I will go into the wifi settings, and I can see the SSID, and it will usually show at least 2 or 3 bars of signal, but when I try to connect, I get a message "Unable to connect to xxx". I fired up the built in Wi-Fi Diagnostics tool on my mac, and when I am right next to the router, I get a signal of -7, when I walk about 5' away, it goes to -27, then when I walk down the stairs to 1st floor, and to mid point of house, I get about -59, then when I continue to opposite end of house (downstairs and 50' away), it drops to about -78. I tried changing the Beacon Interval from 100 to 50, and the RTS Threshold from 2347 to 2304, both were recommendations I read online, but that did not fix anything.

At this point, I am thinking that rather than use the Amped external antenna, is there a way I can just add a 2nd AP via ethernet to the location where I ran the 125' cat5e cable to, which would extend the network, and use the same SSID? then I would have one on each end of the house, and no matter where I am, I should get a good strong signal. Really, spending extra $ on this is not an issue, I just want to be able to stay connected with great signal anywhere on the property.

btw, my SSID is called HOMEWAP, which is pretty unique to what I see on my scans. There is one HOME-2142, but that is only thing close to name. Also, all networks on the scan are 2.4Ghz, I am the only one with dual band, but most of my clients cannot see the 5Ghz, so I stick to the 2.4. The best signal I get from any of the other networks on the scan is -67, the rest are in the -85 to -93 range.

 

[CaptainSTX]

Additional AP

Your proposed solution is correct and will work. I would not put both WiFi APs on the same channel and I would assign each AP its own distinct SSID. WiFi clients will not automatically attach to the strongest signal automatically so being able to identify the nearest and probably strongest signal is by name is the best way to proceed. For convenience you can use the same paraphrase for encryption on both.

If you have a few bucks that you are willing to spend on this project I would use the following equipment.

1. The cheap switch plugged into the Comcast modem should be replaced with a switch with Gigabyte ports. This should eliminate the possibility of the 125' run to your new AP being a bottle neck.

2. At the other end of the 125' cable use a router that can be set up as an AP. It will also need to have Gigabyte LAN ports. One of the LAN ports on the new router/AP will be connected to the 125' cable. The other three ports will be available to connect other devices using Ethernet. If you need more Ethernet ports at either end you can plug one of your current switches. It would be best if you need more than three Ethernet ports on the switch that is connected to your modem to buy a gigabyte switch with eight or sixteen LAN ports instead of a four port switch.

3. If after you get everything set up, the gigabyte switch/ router(s) at either end of the 125' cable doesn't indicate that it has a 1000 Mbps connection you may have to replace your existing cable with a Cat 6E. Try what you have first.

 

[coxhaus]

I have a long house with lots of walls and you could not pickup my wireless network at the other end of my house so I added a second wireless device. I run both on the same SSID but on different channels 1,6 or 11. It works well enough to make my wife happy.
When you setup the second wireless AP play around with the SSID and channels and see what works best for you.

 

[cholmes28]

Thanks Captain - the non managed switch I have, has Gig ports already. As far as the 2nd AP, I am a bit confused about the the reason for giving it a different SSID. Are you saying that if both AP's have same SSID, that the client will still be connecting to one or the other initially, then when I move away from one, and closer to another, the client will remain connected to the first one, regardless of whether the signal is weak, and there is a stronger signal from the 2nd one? If yes, then how is it that large office buildings which have many AP's are able to keep clients connected as they move thru out the bldg?

If I go with different SSIDs, will I still have access to all devices on the network, and will all devices be able to communicate with each other, regardless of whether they are patched to the router or the 2nd AP?

 

[CaptainSTX]

Thanks Captain - the non managed switch I have, has Gig ports already. As far as the 2nd AP, I am a bit confused about the the reason for giving it a different SSID. Are you saying that if both AP's have same SSID, that the client will still be connecting to one or the other initially, then when I move away from one, and closer to another, the client will remain connected to the first one, regardless of whether the signal is weak, and there is a stronger signal from the 2nd one? If yes, then how is it that large office buildings which have many AP's are able to keep clients connected as they move thru out the bldg?

If I go with different SSIDs, will I still have access to all devices on the network, and will all devices be able to communicate with each other, regardless of whether they are patched to the router or the 2nd AP?

Search this site as this issue has been discussed many times. The short answer is that SOHO grade routers and APs don't have this capability. The main problem is the adapters in PCs. Smartphones, etc. aren't smart enough. It isn't a required feature in WiFi standards. It is possible to do what you want automatically using commercial grade equipment and a managed network.

If you set your primary router to handle all DHCP assignments and your APs are set up to be just that then you can share all resources on your network with no problem. If you need more detailed instructions search this web site for information.

 

[cholmes28]

Thanks for clearing all this up, everyone has been very helpful. I am now convinced that I will be better off ditching the external hi gain antenna, in favor of adding an AP to opposite end of house, and wiring directly to the router. Now the question comes up of which AP to buy. If I want to stick with Asus, the only option is this one - http://www.asus.com/us/Networking/EAN66/. Anyone used this one, or have any other suggestions?

 

[CaptainSTX]

As long as the switch at the far end of the 125' cable has gigabyte ports also I would say go for it. Just plug the repeater into one of its LAN ports.

I have never used the ASUS device you are thinking about, but everything I have from ASUS has worked well.

 

[Fraoch]

If I want to stick with Asus, the only option is this one - http://www.asus.com/us/Networking/EAN66/. Anyone used this one, or have any other suggestions?

Note - any wireless router can be used as an AP, just follow this:

http://www.smallnetbuilder.com/wire...onvert-a-wireless-router-into-an-access-point

So you can just get your favourite router and use it as an AP, you're not limited to just looking at APs (which usually cost the same as a wireless router anyway for some reason).

The ASUS RT-N12 even includes a switch to convert it to an AP:

http://www.asus.com/Networking/RTN12/

(not that I'm necessarily recommending it - it's just a single-band N300 router, but it's neat anyway).

 

[Mike_G_D]

Just some observations concerning your "external high gain antenna". Is this what you are talking about: http://www.ampedwireless.com/products/sb1000.html. If so, that is not just an antenna but also includes a transmit power amplifier (unsure if it also includes a receiver preamp). The whole thing is tuned for the 2.4GHz band which means it will not help for 5GHz and may even hurt 5GHz range and overall operation. Also, I am assuming that you simply picked one of the Asus RTN66U's antenna ports and connected it.

This is a problem with using external antennas on the newest dual band multi-stream routers. Firstly, there aren't many actual "dual-band" 2.4GHz and 5GHz antennas and secondly, the nature of the multi-stream design using multiple antennas means that optimally using external antennas can be problematic. Granted, you wouldn't expect true three-stream (or whatever) performance at significant distance but replacing one of those antennas with a completely different design (not to mention one with a built-in amp) will introduce significant imbalance in the RF multi-stream performance such that you may experience destructive signal combining or at least random results not designed for by the manufacturer. Also, depending on the design of the router RF internals, presenting the final amplifiers with an unsuitable impedance load (by using an untuned antenna or external amplifier) which would be the case when attaching a 2.4GHz antenna or amp to a 5GHz transmitter amplifier, damage could result to the internal transmitters or amplifiers. I suspect that most designs probably include robust protection against bad antenna mismatches but I don't know for sure. At the very least, the poor SWR introduced by mismatched antennas and/or external amplifiers will add another random element to the multi-stream design with largely destructive contributions.

Also, if I am right about which external antenna you are using - the one including an external amplifier - then know that, even ideally, an external power amplifier will only boost your transmitter power and do nothing for improving your receive path (the one transmitted from the client to the router unless it also includes a receive preamp; and even then, those designs vary significantly in their effectiveness and poor designs can make things worse).

If you aren't using any devices that use the 5GHz band you might want to disable the 5GHz transmitter in the router altogether - that would at least eliminate that issue when using the 2.4GHz antenna/external amp.

I come from a background in RF engineering so these things stand out for me. You've stated you're planning to ditch the external antenna anyway but I thought I'd add my observations.

-Mike

 

[cholmes28]

Thanks to all for the help. I ended up buying the Asus EAN66 AP, and hardwiring it to the opposite end of the house and on the first floor, and gave it a different SSID. It actually provides me a more stable connection than the primary Dark Knight router. That being said, I have not dropped a connection since.

I did notice that there is still decrease in speed when on wireless. If I sit in the middle of the AP and the router, I get about -48db on the signal strength from both devices, and the AP only gives me 26 Mbps, while the primary router only gives me 15Mbps, but a wired connection gives me 52Mbps. Even if I put laptop right next to router, where I get a signal strength of -7, I still only get about 35 Mbps. In theory, if my router and AP support up to 450Mbps, and my broadband is 50Mbps, then shouldn't I get same speed on wireless as on wired?

 

[Fraoch]

In theory, if my router and AP support up to 450Mbps

Marketing deception - that's the link rate and never reflects actual speeds.

Actual speeds are here:

http://www.smallnetbuilder.com/lanwan/router-charts/bar/111-2_4-ghz-dn-c

The N66U should still be able to pass 50 Mbps with ease at short range according to that chart, but I tested mine with iperf and couldn't get much more than 25-30 Mbps with the client in the same room (that's on 2.4 GHz with 20 MHz channels).

Wireless is still very finnicky and unstable - as you found, wired is always better. Perhaps you have interference or perhaps your configuration is not optimal.

Things which will improve wireless speed:

- 40 MHz channels on 2.4 GHz, but in practice this is very difficult to achieve if there are competing networks in range

- larger external antennas on the client, as opposed to the tiny antennas in USB adapters and the small antennas in internal adapters

- 5 GHz. This is your surest bet for fastest speeds, particularly at short range. See here:

http://www.smallnetbuilder.com/lanwan/router-charts/bar/113-5-ghz-dn-c

Plus 40 MHz channels in 5 GHz is more likely to succeed.

On 5 GHz with 40 MHz channels I was able to get ~125 Mbps which is close to what Tim measured.