this must be a FAQ but I could not find anything.
When is support for the proposed 802.11n standard planned?
I know it’s still in draft state. But since other vendors already sell
equipment based on the draft I have customer requests.
Thanks
Ekkehard
we are working on it. no specific release date has been announced.
Try a search of the forums and you’ll see that this is a hot topic and there are a ton of people asking about this. Mikrotik’s official line is that they aren’t going to announce a date because “programming doesn’t work that way” and they could run into issues or bugs that were unexpected and miss their date. I think it is safe to bet that around 3.10 or so they will have some 802.11n support. The other issue revolving around N is that right now everything is only Draft gear and therefore could be totally different with a new draft or when they finalize the standard, that makes it hard for anyone except the vendor to support the gear. If you need 802.11n right now, check out the Ubiquiti SR71’s using their RadioDriver madwifi based driver.
I think 802.11n is more a fashion that makes the industry sell. For indoor it will improve speeds, so customers can now browse their broadband (1Mb?-2Mb-3Mb? whatever!) connection with their laptop even faster! 
What a joke! I sell my customers ordinary 802.11b/g wifi routers because my internet connection to them comes with 3Mb only! And in a normal house the speed of such routers towards the clients laptops is good enough to consume the internet speed even into the deepest corners of their house.
There is no gain in very high indoor speeds unless you are a freak multimedia user that needs to transport big files within his own network. So the ´n´ protocol is more a fashion, but sadly enough it will dominate the market, like all fashions do.
But read this article, already two year old: http://80211n.wifinetnews.com/archives/2006/02/outdoor_n_speed.html I wonder what the experts will say about this?
It means that a WISP has probably nothing to gain from the ´n´ protocol, unless he would be dealing with a heavy urbanised ´concrete´ environment.
But since most of us Wisp´s are probably in open spaced areas and always are used to as big as possible LOS space we won´t benefit of the ´n´ standard.
Unless the experts can show us it might benefit in a forested area I see no use for ´n´ in the average ´wisp´ world.
rgds
not really, the indoor laptop users would benefit from local network file transfers, now that remote backup (ie. apple’s time capsule) and file storage is becoming more popular, faster wireless in local network is very important.
I do have need for 4-5Gb file transfer from one laptop to another, and usually there is no flash storage around.
Well, we are both right.
The indoor user might benefit if he is working of an outdoor AP, which therefore will be one not to far away (otherwise not enough signal in the house). And off course the benefit in indoor situations is there.
I was more referring to the situation lots on non urban Wisp’s face. Point to Point and Point to Multi Point over distances in open environments won´t benefit. And off course backhaul links over distances not at all. There is hardly or absolutely no multipath radio links.
The only case I am wondering how the ´n´ standard would perform is in an relative close proximidity environment like estate with villa’s etc and lots of trees. So distances are not too big and multipath connectivity between AP and Client (outdoor CPE-units) might exist due the many reflective surfaces around.
It would be nice if under such conditions even NLOS would give highspeed possibilities.
rgds.
well I hope nobody is looking at N as some kind of cure-all for all wireless issues. Of course, as you say - benefits will be only in some situations, and mostly where there are reflections. N is not something that will replace b/g in any wireless installation.
will N help in a ptp outdoor scenario to backhall our Aps?
My ptp links are about 10-15km.
will N be able in this case to reach 80mbps fullduplex?
Regards
N isn’t meant for P2P links… The thread already spells that out…
Wounder why Ubiquiti are touting the SR71 5Ghz N card as the card for outdoor PTP links?
Fashion sells…
Maybe. Or perhaps they have actually tested what we have all been theorising. My guess is the SR71-5 only has 2x2 format so you can connect to dual pol antennas which would make use of any signals that had relected/spun. If that’s the case then these cards could be good for near or none line of sight links.
n is something like N-Stream in mikrotik.
It uses 3 different channels 1,6,13 or 11 and bonds those 3 connections which is approx. 108 or 125 mbps.
So you’ll have to use 3 antennas on your system.
On the other hand you may buy 3x R52H and 433 or 600 and make n-stream.
You are wrong. Read here:
¨n¨ is, as I understood, developed to make use of the fact that in an environment where the signal between one antenna and another gets deflected and bounced through walls, ceilings, constructions or other surfaces deflecting radio signals, which normally cause noise and interferences and actually declines the throughput of the radio link, the ´n´ protocol makes use of these extra radio signals travelling between the both antenna’s. By smart use of this data can be send through several antenna’s in the same frequency and the receiver picks it up at even so many receiving antenna’s. Every radio link can contain data and all the processing unit now needs to do is to make sure data is pack and arranged in the proper order again. This way much more data can be transported on one frequency in the same time frame as on the simple a,b or g protocols. But, all on the same frequency though, so in that respect the remark of sarpkaya was not right.
The ´n´ protocol therefore turns the negative side effect of deflections into a positive one and uses several data streams on the different signals reaching the receiver.
This same effect makes it therefore a technique that hardly works on long bachhaul links with narrow focussed directional antenna’s. Just because of the simple fact there are hardly any bounced or deflected signals that reaches the other end. So the receiver only gets one radio signal which can only carry so much data.
You might now think that by using the same high db directional antenna’s on each of the three antenna points of a ´n´ card and thus make sure three parallel radio signals could be used and thus profit from the ´n´ protocol this way.
But now each radio link would arrive at exactly the same time on the other end and because they are al in the same frequency we have a big interference problem. So big we probably have no workable signal left.
The ´n´ protocol works with, and its actually depending on, the fact that each deflected radio signal has a very small time difference compared to the other from the same radio which gives the receiving radio the change to separate the radio wave and then the cpu combines the data to reach the goal of high throughputs.
It´s clear that this technique is hardly possible in long distant backhauls.
Apart from the fact that in respect of higher radio powers needed and redundancy of the link it might be wiser to use dual n-stream to reach high throughputs.
Rudy
well , my point is: 11n is very useable for distance ...
me and my partners have successfully setup links with 802.11n cards , just using single radio, turning off the 2x extra radios of the Ar5008 chipset in this case (there are also 2x2 RX/TX version available soon) ... with xscale based board and some firmware other than mikrotik os on a 1.2 kilometer link
Platform xscale (533Mhz) 2 AR5416 cards
Firmware Version: other firmware than mikrotik
Regulatory Germany
Channel 5650
Fast-Framing
WPA2-PSK-AES
Linux Server <-> WDS-AP <->WDS-Station <->Linux-Server
[ 5] local 172.27.0.3 port 55446 connected with 172.27.0.75 port 5001
[ ID] Interval Transfer Bandwidth
[ 5] -0.0- 1.0 sec 8.57 MBytes 71.9 Mbits/sec
[ 5] 1.0- 2.0 sec 8.89 MBytes 74.6 Mbits/sec
[ 5] 2.0- 3.0 sec 8.87 MBytes 74.4 Mbits/sec
[ 5] 3.0- 4.0 sec 8.87 MBytes 74.4 Mbits/sec
[ 5] 4.0- 5.0 sec 8.87 MBytes 74.4 Mbits/sec
[ 5] 5.0- 6.0 sec 8.87 MBytes 74.4 Mbits/sec
[ 5] 6.0- 7.0 sec 8.61 MBytes 72.2 Mbits/sec
[ 5] 7.0- 8.0 sec 8.87 MBytes 74.4 Mbits/sec
[ 5] 8.0- 9.0 sec 8.87 MBytes 74.4 Mbits/sec
[ 5] 9.0-10.0 sec 8.87 MBytes 74.4 Mbits/sec
[ 5] 0.0-10.0 sec 88.2 MBytes 74.0 Mbits/sec
[ 5] Server Report:
[ 5] 0.0-10.0 sec 88.2 MBytes 73.9 Mbits/sec 0.110 ms 0/62900 (0%)
[ 5] Sent 62900 datagrams
i hope that mikrotik os can do the same someday , because my costumer asking me frequently for 11n cards that are supported by mikrotik os ....
Am I right in saying that this would be using 40MHz of bandwidth? If so, can’t you get better throughput using RouterOS, R52’s and turbo (i.e. 40MHz)?
[/quote]
Am I right in saying that this would be using 40MHz of bandwidth? If so, can’t you get better throughput using RouterOS, R52’s and turbo (i.e. 40MHz)?[/quote]
no you cant do it with a single radio..
its like 150mbit/s over the air rate… in which you cant achieve it with a single radio currently with MT..
Not sure I completely agree on this.
Both technologies below appear to be part of ‘N’, and both will help in long-haul.
Channel Bonding is a second technology being incorporated to 802.11n which can simultaneously use two separate non-overlapping channels to transmit data. Channel bonding increases the amount of data that can be transmitted. Payload optimization or packet aggregation is a third technology in 802.11n which means more data can be incorporated to each transmitted data packet.
Where we are, we pay the same for a dual polarity antenna on a big tower as we do for a single polarity, so MIMO is a very useful technology, at least 2x2 is.
George
You missed my point. Hebeda was saying that with a third party piece of software using MIMO they where able to get 71.9 Mbits/sec and I was pointing out that MT+turbo you can get better results whilst still using 40MHz bandwidth.