GSM amplifier/repeater

Forums › One New Zealand (including Vodafone, WxC, Farmside) › GSM amplifier/repeater

stevenz

2802 posts

Uber Geek

#29521 10-Jan-2009 14:24

Where I live in Wellington (in Highbury above Aro Valley, about 2Km from the CBD as the crow flies and with line-of-sight to the Mt. Vic radio antenna (yes I know it doesn't have a GSM antenna on it :) - our Vodafone cellphone reception is hopeless. 3G is basically non-existant, and 2G goes from virtually nil to around 80% at random times. This is with a couple of different phones (SE W900, Nokia 3100-series, Nokia 6310, iPhone 3G) - all have different success levels, but none are great (the Nokias are 2G only obviously). Obviously Vodafone aren't going to be interested in putting an antenna in anywhere around here (assuming they could find somewhere) as there'd be a fairly small number of houses around here in the GSM-shadow I'd imagine. I was contemplating looking at some sort of GSM repeater that I could mount on the outer edge of the property where I can actually get a signal (line of sight to Majestic Center etc.).

Has anyone ever had anything to do with these things? Do they work in a residential environment?

Interestingly my father lives maybe 500M from the middle of Nelsons "CBD", and his 3G reception is virtually non existant as well (tried a Vodem and my SE W900i) - is their 3G coverage still as poor as it seems, or do I just have bad luck with the locations I'm trying to use it?

I work just around the corner from the Vodafone building off Midland park in Wellington, and unsurprisingly the phones all work fine there, although the Vodem is still a flaky piece of junk. Fine when it works, but it's very hit & miss regardless of signal strength.

alexx

867 posts

Ultimate Geek

#188575 10-Jan-2009 14:57

I don't think Vodafone would be very happy with the idea of people putting up repeaters and there is potential for a repeater to introduce noise into adjacent bands which could affect other services, such as nearby Telecom mobiles and UHF TV.

Most of these repeater type devices are reasonably broadband, so in the uplink direction they will be amplifying 890 - 915 MHz for GSM900 and probably a few MHz either side of these frequencies. However, Telecom GSM850 will probably be using something like 870 - 890MHz (not sure of exact allocations) in the downlink direction. The band defined for GSM850 (downlink) is 869 - 894MHz (but not sure how much is allocated to Telecom), so there is quite a strong potential for interference between these systems unless they are well managed by the operators.

Have you talked to Vodafone and asked them if they have any plans for improving coverage in the area?

sbiddle

30853 posts

Uber Geek

Retired Mod

Trusted

Biddle Corp

Lifetime subscriber

#188580 10-Jan-2009 15:09

First off I'll mention that such devices are illegal in NZ unless you have management rights for the spectrum. HYou will be breaking the RSM rules and the fines for breaking these can be quite steep.

Having said that there are devices being used in NZ and if you have a look at www.mobilerepeater.co.uk you will see some very good quality units for same. Price is probably an issue but if you are after a quality device then that's the price you have to pay for a decent unit. Plenty of the cheap Chinese units will cause network interference and you will be hunted down if you are causing issues!

Vodafone themselves install similair units to deliver coverage into some deadspots. UK carriers seem to be taking a hands off approach to these devices, officially they try and discourage use but if users are finding solutions then at the end of the day it saves them spending money on network infrastructure!

stevenz

2802 posts

Uber Geek

#188598 10-Jan-2009 16:21

Seeing as how difficult it is getting through to anyone at Vodafone who has a clue for even relatively simple matters, I'm somewhat hesitant to try asking them for anything as technical as something involving tower-installations, but I may have to do so. Maybe I'll get lucky :)

I see that some company with no address on their site, "Quantel" in AKL is selling a 900Mhz CDMA/GSM booster for about $400, although that's 2G only so not hugely helpful.

From what you guys say though, it looks like I may just have to ask Mr Vodafone very nicely... I wonder if they'd give me a subsidy if I let them strap a tower to the garage? :)

alexx

867 posts

Ultimate Geek

#188600 10-Jan-2009 16:27

sbiddle:
UK carriers seem to be taking a hands off approach to these devices...

The situation in the UK is a little different, as to the best of my understanding they don't have GSM850, so no problems with adjacent Uplink Tx (GSM900) and Downlink Rx (GSM850/WCDMA850) in the region of 890MHz. Over in the UK they have GSM with (correct me if I'm wrong) E-GSM channel allocations where all the uplink channels are together (880 - 915MHz) and the downlink (925 - 960 MHz) has some separation.

The frequency allocations here in NZ, date back to the early 1990's, where the spectrum was actioned off according to "free market" policies and both AMPS and TACS frequency bands were offered. Telecom got both AMPS 'A' and AMPS 'B' and Vodafone (then BellSouth) got TACS 'A'.

The result was interference from AMPS base stations transmitters to the GSM BTS receiver (when the base stations where close to each other). When you used a GSM mobile within a metre of an AMPS mobile, it was not uncommon for the AMPS mobile user to hear a loud buzzing sound from the interference and sometimes even a dropped call.

While the frequency allocation issues have been worked on and the problems greatly reduced since those early days, the use of these adjacent Uplink and Downlink frequency bands mean that Vodafone and Telecom need to be a little bit more careful in managing these bands than operators in the EU who don't have these same inherent interference problems.

bbman

646 posts

Ultimate Geek

#189588 14-Jan-2009 17:21

Further to this, up until recently Vodafone had a booster option on their website but when i saw this post i looked for it and the link goes to their shop front page now.

One major Telco banned its dealers and stores from reselling boosters only a few months ago, i support that because a niche specialist slightly contraband product was being put in the hands of idiots in retail stores to sell and thats not a good look and could cause problems.

Word of advice, be very careful what you buy from over seas and NZ, there are some cow boys out their selling gear.

The new femtocell products coming in the near future will help eliminate coverage issues for some people with in ADSL or fibre coverage but the major users and buyers of amplifiers are those in the rural, emergency and marine sector, where neither Telecom nor Vodafone have adequate coverage. Often they have no choice!

There is a niche market for them, the smart resellers with quality gear dont advertise or rave about them but through word of mouth and customer need move units.

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