Wireless-N Experiences

[ldavis]

I recently bought a new laptop and have a wireless-n adapter built in so I decided to try out some of the draft-n routers out there to see if this new technology lives up to its billing. I have the following observations:

1. Extended range – That’s a fact. My house is a wireless hole, and to get 802.11g to work consistently throughout I have had to buy extenders and antennas. With draft-n, I get consistent speed and connection quality with only 1 access point
2. Enhanced speed – Well, not so much. Numbers like 300mbps are a dream at this point. I was able to get 130mpbs which is an improvement but well below the target, and these numbers were from all over the house including 2 feet from the access point. To be honest, my sole interest in draft-n is to be able to wirelessly stream HD content. In theory 130 mbps should be enough but it is not even close.

What are others experiences with this still developing technology? I certainly hope that this is improved prior to the final draft. If not, it will be many years before we are able to wirelessly stream HD. In any case, the routers went back to the store since at this point draft-n does not offer anything that I want.

[UFGrayMatter]

I built an HTPC for somebody else - had it for about a month and it was rock solid.

Installed it at his place w/ a new wireless N pci card - caused BSOD's - googled it and saw it had lots of problems. Fixed it by downing power by 50%

[sainswor99]

I just went with wireless-N in my house; my setup prior to this was three routers (2 in bridge mode), and I was still not getting total coverage. Part of my issue is that my wife is a Luddite; as long as she can't see something, she's OK with it. I was having trouble finding places to hide the routers (I had thought about hiding them in the walls, but didn't go that far).

Anyway with wireless-N (Belkin, BTW), I was able to get 300M in the room next door to my main router; at my farthest point in the house 2-11M. Not bad for placeshifting, but certainly not HD quality. I wish that there was a wireless-N bridge available, but perhaps that will come.

I do find that range and speed are drastically overrated; my house is not that large. The footprint is only 50x30; it is a two story, and I understand that the bubble does affect the range (as do the walls, the electrical, the people, butterflies in China). But still, they advertise 800 feet for these things.

Stu

[ldavis]

So some of you are getting 300 mbps?. When I was auditioning the dlink router it would default to 78 mbps unless I forced it to a higher rate in the setup but the absolute highest that could be forced was 130 mbps. How are you getting 300?

Also, if you are looking for a bridge, couldn't you buy a second router and turn off DHCP. Then it would just be an access point just like you have done for for former 802.11g network.

[sainswor99]

That's basically the setup for the wireless G bridges I have; they're routers in a bridge mode. However, AFAIK (and I'm not a networking guy) the two access points have to know about each other in order to build a wireless bridge. As far as I can tell, no wireless N router supports a bridge mode. Perhaps someone has hacked together a custom firmware, but as of yet I haven't seen one.

Stu

[thatdude90210]

Maybe I'm mixing up the bits bytes thing. But isn't 130mbps greater than most 100mbps LAN lines? Even the HDhomerun is a 100mbps device, and it can stream 2 HD channels at the same time.

I've tried streaming HD videos (recorded using HDhomerun) on my Sageclient via wireless G (Dlink dgl 4300 router to Buffalo wireless ethernet bridge). Using network status on taskmanager, I think I'm getting about 20mbps. Streaming 720p is fine, but 1080i stutters. So wireless G is almost there for me... that's why I had thought that wireless N would do the job.

Or are you talking about streaming HD DVD / BluRay?

[ldavis]

Originally Posted by thatdude90210

Maybe I'm mixing up the bits bytes thing. But isn't 130mbps greater than most 100mbps LAN lines? Even the HDhomerun is a 100mbps device, and it can stream 2 HD channels at the same time.

I've tried streaming HD videos (recorded using HDhomerun) on my Sageclient via wireless G (Dlink dgl 4300 router to Buffalo wireless ethernet bridge). Using network status on taskmanager, I think I'm getting about 20mbps. Streaming 720p is fine, but 1080i stutters. So wireless G is almost there for me... that's why I had thought that wireless N would do the job.

Or are you talking about streaming HD DVD / BluRay?

That is exactly my point. I am talking about OTA HD and 130 is greater than a 10/100 wired network but I think that there is just so much overhead that I cannot get it to work.

I just checked and I like you have been able to get 720p to work but amazingly 1080i actually works better with 802.11g so maybe there is some hope once the standards are finalized. Maybe there is something right now that is preventing a video streaming app from working as well. Mabye I need to go get another router to see if I just need to adjust the setting some more. The one problem with 802.11g and streaming is that you have to have a prefect signal to have a chance. Hopefully if they get some of these issues working with the finalized N, then we will have some overhead

[GKusnick]

In my experience with wireless G, the numbers don't mean much. To get an idea of how well it will work under real-world conditions, try it when it's raining outside, with a bag of popcorn in the microwave, and a couple of wireless laptops websurfing at the same time.

[ldavis]

Originally Posted by GKusnick

In my experience with wireless G, the numbers don't mean much. To get an idea of how well it will work under real-world conditions, try it when it's raining outside, with a bag of popcorn in the microwave, and a couple of wireless laptops websurfing at the same time.

Agreed!!!! As an adder to my previous post, I am thrilled that someone can stream HD at 20 mbps but for me unless I am in the room or right next door ( and at 54 mbps) then streaming even 720p is a no go. But based on these tests, I think there is something in my draft-n card driver or the router firmware that is messing this up because the through put that I am getting should work based on 802.11g being somewhat close.

[hemicuda]

I can speak towards the overhead being a major issue. I store a handful of DVDs on a linux box that also doubles as my firewall/router. I had a coding error that was adding my IP blacklist to iptables every day instead of replacing it. After less than a week my LAN throughput went from 56% in task manager to 5%. Needless to say I could barely stream AVIs let alone DVDs. Having to wade through 1200 lines (per day the script had run) of blacklisted IPs for every packet really puts a crimp on things.

[sainswor99]

Just did some poking around; latest firmware on the Belkin N1 router has a hidden config page for wireless bridging (http://192.168.2.1/wls_wds.html).

I haven't had a chance to test it, yet, but if anyone else has a couple of Belkin routers laying around, it may be worth trying.

Stu

EDIT: Just tested it with a belkin G and I couldn't get it to work. Sigh.

[paulbeers]

There are several factors:
1. Overhead due to encryption, and other factors. I once read an article comparing 54g routers and the fastest only averaged 16mbps and the slowest was 9mbps when transferring files (Windows stated it was connected at 54mbps). That would mean that even if you were "connected" at 300mbs, you would max out at 89mbps in actual bandwidth (16mbps / 54mbps = 30 percent) and 60mbps on the slowest.

While those speeds would be able to handle an HD stream....

2. The biggest culprit, packet loss. There is the big issue. When surfing the internet or transferring a file, if a packet is lost, our systems just request the packet again and in a fraction of a second we have the webpage/file we requested. The problem is that fraction of a second means that we could have lost a a frame.

While we are still using the 2.4 ghz bandwidth for our wireless networks (yes I know 5 ghz bandwidth is available but expensive) that is very over crowded, we will have lost packets.

Just my .02 worth.

[stevech]

11n does not require, but some vendors are using two channels for 40MHz of RF bandwidth. That's 2/3 of the entire band. With this (non-neighbor-friendly) arrangement, you get double the throughput. BUT, some have decided to not bond pairs like this if any 11g signals are detected in either channel. Thus, it's often overridden. I think some products allow you to choose the spectrum hogging mode even if 11g systems are in range.

Of course, the speed you get at the IP layer is about 60% of the air link speed(s). This is mostly because 802.11 is CSMA/CA and also, each frame sent must be ACK'd. Unless you burst frames without ACKs - and the technique for this is non-standard.

And the air link rate you get is determined by
1. Signal strength and signal to noise ratio. You need a very strong signal, like -70dBm or better to get the highest air link speeds.

2. Amount of competition for channel-use time. Your neighbors' signals, if busy, deny you air time and effective througput. And vice-versa. Hence the 40MHz mess.

3. Amount of interference from non-WiFi sources like cordless phones.

4. Fade margins - you need that -70 or better signal to allow, say, 5dB of fading.

5. Obstructions in the path from to the receiving antenna. Line of sight rarely exists. Elevated antennas, even on top of furniture, help. Directional antennas are the panacea.

Wireless should, as we all know, be the last resort, when you cannot run wire. Or you are mobile/nomadic.

The interference with 11a is a lot less. But it's stuck at 54Mbps air link rate. And the 5.8GHz signal propagates a bit more poorly than does 2.4GHz.

[ldavis]

Well, I went back and tried the Dlink 625. There are probably a lot better solutions out there but for $80, I'll give it another shot. I do not know what I did differently but HD streaming works at every point in my house. I still only get throughput ranging from 130 to low 50's mbps so I will stand by my earlier statement that draft N does not live up to its promise about speed. I will be using this for the next few days to see if there is any interference that will prevent my using this as a permanent solution. Still, since my only interest here was HD streaming, as long as this performance continues, I'll be happy.

[stevech]

Originally Posted by ldavis

Well, I went back and tried the Dlink 625. There are probably a lot better solutions out there but for $80, I'll give it another shot. I do not know what I did differently but HD streaming works at every point in my house. I still only get throughput ranging from 130 to low 50's mbps so I will stand by my earlier statement that draft N does not live up to its promise about speed. I will be using this for the next few days to see if there is any interference that will prevent my using this as a permanent solution. Still, since my only interest here was HD streaming, as long as this performance continues, I'll be happy.

those are twice the IP layer speeds I've seen in plain 11g systems with a strong signal.

Don't forget about the possibility that (a) your w-router and clients weren't designed for channel-pair bonding (not required by 11n), or (b) that the presence of any other systems with 11g clients may cause yours to drop back to one (20MHz) channel.

[lparkin]

I use a dir 655 N with its associated pci adapters in my sage computer and am getting 250 to 300 showing in the client on the pvr...and can stream everything.

I had to use an external antenna mounted about 3 feet above the pvr to get a consistent signal. I have the router on the upper floor above my garage while the pvr is on the main floor. I am pretty pleased with it.

I have storage for archived and imported videos on another machine that is hardwired to the router...but can play those with no issue. I also have tested that with the storage location using wireless N and can stream from it with no issues.

[stevech]

Originally Posted by lparkin

I have storage for archived and imported videos on another machine that is hardwired to the router...but can play those with no issue. I also have tested that with the storage location using wireless N and can stream from it with no issues.

You're speaking of HD TV, I assume. Streaming SD works just fine with 11g speeds of 36 and 54Mbps air link rates. I'm guessing SD streaming of mpeg2 takes about 4-6Mbps at the IP layer, and that needs to be on an underutilized channel so there's room for occasional retransmission delays in the wireless medium.

[ldavis]

Originally Posted by stevech

those are twice the IP layer speeds I've seen in plain 11g systems with a strong signal.

Don't forget about the possibility that (a) your w-router and clients weren't designed for channel-pair bonding (not required by 11n), or (b) that the presence of any other systems with 11g clients may cause yours to drop back to one (20MHz) channel.

I do not have any other clients on this system so the answer is A. It is really a shame that 11n does not require this as a std. Likely, we will end up with vendor proprietary solutions so that you will have to have routers and cards from the same vendor to achieve the 200+ mbps rates. That bothers me as far as a laptop is concerned since I do no want a card hanging off the side of my machine, and from what I see most of these guys to not offer an internal card.

[autoboy]

I researched N hardware but settled on MIMO G. The Airgo gen3 chipset can support 240mbs speeds and has very good range. One of the advantages of this setup is that it is not neighbor friendly. It pretty much squashes other G networks out there which reduces the chance of interference. My neighbors have G and some B but houses are far enough appart not to make a huge difference in their speeds. They are getting hard to find as they are replaced by N hardware.

I have a Netgear Rangemax 240 that I got for $50 (rated one of the best routers on the market for WAN throughput) and a Linksys SRX400 PCI card. Both use the airgo gen3 chipset. I get a 240mbs connection rate and steady transfer speeds of 60mbs for windows file transfers. There is no spikes or packet loss which can kill your connection. This works flawlessly for any HD I have ever tried streaming. I have another G access point for my laptop so I don't bring down the speeds of the MIMO G network. I have never seen any slowdown on the laptop but I rarely if ever use it when I am using the HTPC.

[stevech]

Originally Posted by autoboy

... The Airgo gen3 chipset can support 240mbs speeds and has very good range. One of the [dis]advantages of this setup is that it is not neighbor friendly. It pretty much squashes other G networks out there which reduces the chance of interference.

Some/most 11n draft 2 hardware will not use 40MHz channel pairing if any 11b/g devices of any kind are in range.