Does my Laptop Support 5GHZ?

Dell Wireless-N 1520

Using Inssider I noticed my laptop (Dell Wireless-N 1520) shows a 5GHZ band, but my netbook (wireless G) did not. Investigating a bit more in device manager my Dell wireless Card seems to have an option to prefer a band networks. So my laptop card does support wireless a 5GHZ Band. I ran a speed test and got some surprising results:

Connected to 2.4GHZ Band. 
Link Speed 117 MBPS
Network Utilization during File Xfr 60%
File Transfer on LAN 7.10 MBPS

Connected to 5.0GHZ Band
Link Speed 300 MBPS
Network Utilization During Xfr 12%
File Transfer on LAN 2.10 MBPS

The 5.0 GHZ Router is in same room and in line of site. No walls. Very surprised how sucky it is. Wasn't sure if it was router or the Dell Wireless-N 1520. So I ordered TP-LINK TL-WDN4800 Dual Band Wireless N900 PCI Express Adapter, 2.4GHz 450Mbps/5GHz 450Mbps, IEEE 802.1a/b/g/n, WEP/WPA/WPA2.

TP-LINK TL-WDN4800

Using default driver in W8 (Qualcomm Atheros AR938X Wireless Network Adapter) I confirmed connection on 5GHZ band using Inssider.

Connected to 5.0GHZ Band
Link Speed 450 MBPS
Network Utilization During Xfr 60%
File Transfer on LAN 15.47 MBPS

Definitely not my router. I'd like to compare N speeds on this triple stream card but I see no option in the default driver to prefer the 2.4GHZ band so the only way to test 2.4GHZ would be to use different SSID names for my bands. Maybe later....

ESS (Extended Service Set)

Should I use the same SSID on my 2nd WAP and setup an ESS (Extended Service Set)? Apparently if I configure the same SSID, the same WPA2 Authentication, same Key, etc. on different WAP's. Clients should then be able to roam between them. ESS is often used in company's to increase coverage to wireless area. See here. Another good link. I suppose it also increases fault tolerance. If one router goes down for maintenance the other continues working.

Beside the fact that config settings need to be identical, the main disadvantage is loss of control. From the client we can specify preferred SSID's but that's it. There is no way I can find to pick the WAP with this MAC ID over another with the same SSID. After booting both windows and android clients, each would link to the WAP with the strongest signal. As I roamed I stayed linked to the WAP that I was closest to on boot even when I moved it next room with the other WAP. The signal was still pretty strong so I am not sure what threshold might cause it to re-evaluate. I am guessing it only reconnects when signal is lost? It does not seem to re-evaluate signal strength over time (Unless I didn't wait long enough). With different SSID's when I move my client to another room I could manually reconnect to the closer WAP. With the same SSID I seem to have to reboot. On the flip side, even though I like the idea of control, I really don't picture myself manually doing anything to maximize throughput. Perhaps the same SSID is the best?

Another questions is whether to use the same SSID for the 5GHZ band and 2.4GHZ band on my RT-N66U dual band router. Currently I have them configured as seperate SSID's. Here is an interesting link with a good argument for keeping them the same. inssider does make it possible to detect not only what channel but also which WAP you are connecting to (IT is listed in BOLD Lettering). Also checking the System Log in the router web page we can get a list of connected MAC's.

The more I look the more I see people who like it or hate it. For testing, separate SSID's is definitely the way to go because it gives control. For every day use I am leaning towards the same SSID being simpler. Just google

5ghz ssid and 2.4ghz ssid

Authentication Methods

1. Open System (No Authentication)
2. Shared Key
3. WPA-Personal
4. WPA2-Personal
5. WPA-Auto-Personal
6. WPA-Enterprise (For Company's)
7. WPA2-Enterprise (For Company's)
8. WPA-Auto-Enterprise (For Company's)
9. Radius with 802.1x (For Company's)

As of 2012 WPA2-Personal is the best. All home routers should be set to this. A Shared Pass Phrase must be set on the router and supplied by each client. Encryption uses AES CCMP (Not TKIP as in WPA).

If and ONLY if you have some old device that won't connect then you should use WPA-Auto-Personal. WPA can only use wireless G Speeds. Some recommend setting up a separate WAP to support older clients.

Wireless Router N Speeds

Wireless Routers have the following N speeds in their advertising: N300, N450, N600, N750, N900. Great Link I got this info from. My RT-N15 is an N300 Router. My RT-N66U is an N900 Router.

We also have this concept of mimo streams. single-stream (max 150 per Band), dual-stream (max 300 Per Band), and three-stream (max 450 per band). I think each antenna can broadcast a different stream at a different angle to bounce off a different wall while using the same 20MHZ channel bandwidth. So this triple streaming has nothing to do with Channel Bonding.

So I think my RT-N15 is a dual-stream 2.4GHZ N300 Radio WAP and can do max 130 (20MHZ Single Channel) / 300 (40MHZ Channel Bonding). There is no separate radio for a 5 GHZ band. In single channel Mode inssider reports max rate of 144, not 130? In 40MHZ Channel Bonding Mode I still see Max Rate of 144.

My RT-N66U is a triple stream 2.4GHZ/5GHZ N900 (dual) Radio and can do max 217 (20MHZ Single Channel) / 450 (40MHZ Channel Bonding). There is a separate radio for the 5 GHZ band. While this radio can be active while the 2.4GHZ radio is active I do not think a single client can combine data from both spectrums at the same time. Hence the max 450 and not max 900. In inssider is see max rate of 216.

Most laptops, wireless phones, video game systems, etc. only connect through the 2.4 GHZ band. To take advantage of three streams, and/or 5ghz band you need to buy newer nics. For example this one is 30 bucks at amazon now http://www.amazon.com/Rosewill-Wireless-Adapter-802-11a-RNWD-N9003PCe/dp/B009VKON0S/ref=sr_1_2?ie=UTF8&qid=1360206397&sr=8-2&keywords=n900+pci+express. Here a mini pci express card for a laptop that is dual band three stream. http://www.amazon.com/Intel-Ultimate-633ANHMW-802-11n-Adapter/dp/B0038A9HSK/ref=sr_1_2?s=electronics&ie=UTF8&qid=1360210110&sr=1-2&keywords=mini+pci+express+wireless+card+5ghz

Wireless Channel Bonding

802.11a/n supports Wireless Channel Bonding. Not to be confused with Dual band which indicates support for both 5GHZ spectrum (wireless a) and 2.4GHZ spectrum (wireless b/g/n). As the last post points out channels sets in 1, 6, and 11 in the 2.4GHZ n space each use about 20MHZ of spectrum each. My older RT-N15 WAP supports channel bonding using two adjacent channel sets (40MHZ). This is why in inssider we see a 5+9 and for our neighbors a 10+6. My newer RT-N66U dual band WAP also supports channel bonding but it seems to only use one channel set from the 2.4GHZ spectrum (at least according to inssider). From what I've read channel bonding works best when there is no interference and the 5GHZ address space is less crowded. This requires a nic with an a radio, dual band client wireless nics. None of my wireless nics on my laptops seem to connect in the 5GHZ space. In the Router Home Page we can see a channel bandwidth setting of 20MHZ or 20/40MHZ. The 20/40MHZ setting in the router web page enables channel bonding. In some cases Channel Bonding can even hurt performance, see here. Another thing to keep in mind is that connectivity in the 5GHZ address space has a much shorter range than the 2.4 GHZ address space, however it can transmit much more data when it works. It seems wireless channel bonding (40MHZ) can only be used with adjacent channels. We cannot for example combine one 20MHZ channel from 2.4 GHZ spectrum and one channel from 5 GHZ spectrum.

WLAN Channels

Most like me leave the wifi channel at auto. From what I am reading we can get better performance by selecting a channel. The following page has some info on channels. http://en.wikipedia.org/wiki/List_of_WLAN_channels The thing that confuses me is it best to pick from 1, 6, or 11 OR 1, 5, 9 or 13? I mean who uses wireless B anymore? The following link has a post half way down the page that explains it. http://forums.smallnetbuilder.com/showthread.php?t=7415. We don't realty know if our neighbors are using B. If they are then only 1, 6, 11 are safe. If we all stopped supporting B then 1, 5, 9 or 13 would be best.

There are a few ways we can detect what channels are being used (ours and our neighbors). From cmd prompt on windows 7 we can see channels using the following command

netsh wlan show all

The WLAN Autoconfig service needs to be running to make this work and we need to have a wireless card. So run it from a laptop with wireless. On my Dell Laptop the Dell Wireless LAN Card Utility has a Site Monitor Tab that Lists Channels and Signals. Yet another option is to download inSSIDer. The funny thing to me is none of the tools seem to agree on what is the next strongest wifi signal strength. From my readings I and all my neighbors seem to like 1 most. 11 Next. No one is using 6. The thing is the most important factor is not signal strength it is use. If someone is streaming video on channel 1 we want to switch to channel 6 or 11. The problem is we can't detect use directly. We can only detect signal strength. Still with this information if we find no one on channel 6 then we should use it.

I have tested more and noticed that neither of my WAP routers stick to a set channel on auto, so all of this information on the internet must assume really old equipment. My RT-N66U moved it self to channel 6. My RT-N15 has also adjusted itself on the fly to an area with less channel activity. They both must have the same capability inssider has to detect what channels are in use.

Adding LAN Ports

I have an old Asus RT-N15 Router sitting around doing nothing and was thinking of setting it up in the living room to add more LAN ports and to improve wifi reception as a 2nd AP (Access Point) SmallNetBuilder is a Good site and has good links for subnetting a 2nd router. http://www.smallnetbuilder.com/lanwan/lanwan-basics/30740-how-to-use-a-router-to-add-network-ports?start=1 It turns out in my Administration Tab I can change it from Home Gateway to Access Point. In Access Point mode, four LAN ports in the RT-N15 and other wireless devices are set up in the same local area network. The WAN related functions are not supported in this mode. In this mode, NAT is disabled and four LAN ports in the RT-N15 and other wireless devices are bridged together. In the Manual it mentions that even the WAN port will be modified to work like a LAN port. This should prevent the need for another subnet. I think all I will need is a static IP so I can always remote into this device.