Will External Antenna reduce FER% ?

[Roman4604]

Hi All,

I'm in Lonehill (East) connected to (I assume) the Kayalami (Castle) base station, to which I have line of site & my signal is always 100%. I'm using a UTD with built-in aerial (flashed to latest fw).

My problem is that my Frame Error Rate % climbs to 12-20% when my throughput peaks (best ~700-850 Kbps). Any time my throughput peaks above 450 Kbps it gets slapped back down to about 150-250 Kbps from where it starts climbing again.

This yo-yo'ing of speed/errors results in my average throughput being ~ 320 Kbps (off fast RSA servers).

My question is to those with external (directional) antennas; do you believe an ext. dir. antenna (precisely pointed at basestation) will reduce my FER% noticably, thereby improving my ave. throughput?

Obviously dont want to shell the cash if it's going to do squat.

TIA

 

[slimothy]

It could, it *should* but it might not. If you're already that close to a tower you do not want to go spending money on an external antenna unless you want to try connect to a different base-station. You already have 100% so rather than shelling out the cash I suggest you take out 30 minutes to find your sweet spot, just keep the connection active with a download, and use the iBurst terminal as an indicator and move the modem around bit by bit, should you notice a slight improvment then keep moving it in that direction. I know it sounds cooky but if you only ever listen to one thing I say let it be this.

 

[regardtv]

Remeber of course that the 100% signal indication is the quality of signal received from the tower... not the quality of signal you are sending back.

From some of my playing around a directional antenna could indeed help. I'd suggest you contact WBS, try get a unit on loan (I'm sure they'll invoice you but you should be able to return it if it does not work).

 

[Roman4604]

Hi Slimothy,

I've tried the hunt the "sweet spot" game, but it had vitually no effect on my high speed/high FER% problem. I even got a long extention cord an sat in the middle of my garden with Laptop+UTD, in full view of the Kayalami Castle, and little effect.

I'm theorising (no expert in radio tech) that my problem is not access to & from basestation, but rather some form of interference in my area (Lonehill firestation up the road has big mast with lots of funky aerials).

I'm hoping the focused nature of a directional antenna will allow the UTD to ignore this supposed interference ?

Cheers

 

[slimothy]

yeah that sounds right, BUT do what regardtv says and try it before you buy it, worst comes to worst you could try use the antenna to connect to a different tower.

 

[seburn]

Like bryanston? Nah Stick to kialami.

 

[Roman4604]

Hi All,

Finally got my standard iBurst ext. antenna today directly from WBS and for me it was worth every cent of the R 456 inc. VAT I paid.

Installed externally on my house & pointed at Kayalami Castle. My local download throughput off various SA servers now averages 850+ Kbps. Thats a sustained average on long downloads (> 10 MBytes). Peak continually hitting 1024 Kbps like a car engine being gunned against the rev limiter. To put it another way I'm downloading 1 MByte of data in < 10 sec.

My FER% is slightly less then before (ave. 5% spike to 15%), however its realitively much better, as this is on a much higher throughput. Another nice plus of lower FER% is ping time (to www.iburst.co.za) averaging 65 ms with the odd spike in the 100-200 ms range.

BTW this is using a MTU of 1352 (set on my router) with no RWIN or any other IP stack tuning on WinXP. The above performance was measured on my Laptop talking USB to UTD, however when switched to my regular setup, performance remained exactly the same ...

WinXP Laptop -- WiFi G-->D-Link 624+ Rtr -->UTD-->Ext. Ant.-->Kayalami BS

Just show that the iBurst radio technology, when well tuned, works to spec (no comment on WBS and the rest of the SA iBurst setup). Hope this info helps someone else in the future.

Cheers.

 

[slimothy]

glad to hear it worked for you, however, you might want to tweak a bit more because you really should be getting speeds of 120 - 128 assuming your tower isnt crowded

 

[Roman4604]

Hi Slim,

As as I use my laptop at work & customers to do a lot of sw/tech testing, I'd rather not mess with WinXPs default IP stack settings. 110 KB/s is fine for me at the moment. Might mess with my home desktop PC when I get a gap.

Cheers.

 

[slimothy]

not tweak software, theres not much you can do other than make sure your packets dont fragment (which is what the low MTU is for) but you need to find that awesome sweet spot everyone has in thier house (like behind your fridge or in a cubboard somewhere) but of course that extra 10 - 20KB/s only matters if you plan on downloading huuge files all the time