Breakthrough ADSL booster announced
Dylan Repia, 31 Jan 2005
Telstra today announced what may be a major breakthrough in improving its broadband coverage.
The telco is commencing trials of new device that can make ADSL available up to 20km away from a central exchange.
The Australian-designed device, known as Expandsl, is a tiny, weather-proof DSLAM that is installed at the end of the current transmission limit. Each unit can connect eight end-users.
The devices don't need power or shelter, making them considerably cheaper to install than other extenders like mini CMUXes. They could be left in a pit in the street, clipped to a pole, or bound to a powerline or overhead pay-TV cable.
And they don't need a fibre-optic connection back to the exchange. Instead, they use a G.SHDSL (super-high bit-rate DSL) connection, which runs at 2.31Mbit/s symmetrically.
The units also have ethernet ports, so they can be upgraded to higher-speed IP feeds in the future. They can be upgraded to ADSL2 & ADSL2+ via a software upgrade.
The Expandsl maker's website suggests the units can even be installed at customer premises alongside technologies that have traditionally blocked ADSL, like loading coils and pair gain. But Telstra hasn't said whether it will use them for this purpose, saying only that they can extend the reach of ADSL beyond existing distance limits.
Telstra is also just days away from the conclusion of its trial to see if ADSL reach can be extended by allowing customers to trial ADSL at line signal loss levels up to 80dB. The Current limit is 56dB.
Telstra Country Wide's Doug Campbell explained: "The difference [with the Expandsl trial] is that this device could take ADSL technology to much greater lengths in discrete locations where there are smaller numbers of distant customers requiring the service.
"If successful, this electronic solution will be deployed where necessary to extend the reach of ADSL and be of great benefit to those living between approximately four and fifteen kilometers from an exchange, such as in some outer-metropolitan, regional and rural areas."
The initial trial will take place over three months at Woodend, Merbein, Robinvale and Mt Eliza in Victoria and Mudgeeraba in Queensland.
Links:
- Media Release (Telstra, 31 Jan 2004)
- Expandsl Product Information (Extel Communications)
> I'm impressed with the device - it's FULLY submersible!
Rated for long-term submersion in up to 5m of water.
> they do offer a decent pairgain replacement which works with v.90 modems
I worked on that one too. A pair gain system which has an onboard DSP that detects a v.90 call and reconstructs it at the exchange end. That way, you get a full v.90 rate through a pair-gain system.
Happy day! Nothing feels better than seeing one of your own products ship.... :-)
It was found that a large number of people wanted ADSL but was well out side of the range of ADSL (up 10-30K's) from the exchange but they all lived within 5km from each other, it's not practicable to build a new exchange as the cost beet the returns but this lovely little device is what the doctor ordered.
Not only is it compact it can be expanded on by just adding another module. So if someone subdivides a farm into farm lets (as is happening all around our cities), then it's easy for Telstra to provide ADSL to these new areas.
Saw the heading .. though definate april fools joke..
I wonder if it will ever be used.. Only fro Telstra customers I would guess
I to can't get ADSL and have had to go with ISDN... very ordinary..
Looking forward to the possible brighter future.
And they don't need a fibre-optic connection back to the exchange. Instead, they use a G.SHDSL (super-high bit-rate DSL) connection, which runs at 2.31Mbit/s symmetrically.
So is this standard copper line that allows normal ADSL or is specific for only areas that have this line?
Ex
Adrian
I would suggest not. They talked about connecting it with copper at the end of the current ADSL range. RIMs have fibre back to the exchange and no ADSL to extend.
Nobody knows if Telstra will make use of this version however.
Ya just have to get a giggle out of this little gem. These boards are littered with frustrated people living in inner city suburbs, new sub-divisions and, in some cases, next door to their exchange, who cannot get ADSL. Whoever said Telstra were out of touch was the master of understatements.
On the bright side...whoo hoo...this sounds great. Where do I sign up for the trial :) There was a recent discussion on the ISDN board about BPL. This new technology for extending ADSL would almost certainly negate any need for BPL. Good on ya Telstra, now get on with it :)))
They called it a DSL extenter if I remember. They talked about 50 Kms.
I dont have the source anymore :(
Im guessing someone at 20km distance would get the minimum 256/64k speeds. Then how about someone say 8km away who prior to this was believed to in theory, if they are lucky get a max speed of 256k. Will they now be able to obtain speeds of 2mbit+? What if one of these things was installed near someone ~3km away from the exchange, allowing their shiney new ADSL2 connection of only about 10-12mbit reach 24mbit.
Very curious to find this out and how cheap these things are for telstra to install. If they work as promised this would seriously herald the dawn of a new day for aussie BB.
That idea is that it brings the DSLAM closer to the customer so they can get DSL at all.
What's stopping ISPs to rollout higher speed ADSL services is because the Australian population lives too far away from one another. With these extenders distance is no longer a problem (at a relatively small cost). So, to all ISPs who're rolling out their own infrastructure - we're all hoping for 6Mbps ADSL!!!
.. Well done Telstra for at least "trialling" technology that increases broadband range.
All the talk at present has surrounded high speeds, and how much they will rock.
High speeds are all well and good, but do not help a significantly large proportion of folk who will never see broadband (at least in standard ADSL(1) format) due to range/ line length issues (there are regional area's where even ADSL2(2+) wont be much further help either.
The trial, may only ever be a trial, with nothing good coming of it, but Telstra "appear" at any rate to be thinking outside the "square" they have so skilfully and (in)efficiently cornered themselves into.
This is at least a start.
One thing however... where do we find some solid results from said tests and trials? Unless i missed it some where obvious... :/
My brother lives in Europe is just below 5KM from the exchange.. No ADSL for him for years, it's only last year that they used this kind of booster.
No point blaming telstra on this matter, it's the same everywhere
The highly cynical would say that telstra is most likely to just deploy this technology in a certain few key rural areas so that they can get the telstra selloff legislation past the national party.
this is great news.
This does however, bring me to a point which makes me quite... well... aggitated.
This bagging of PGS is just another way of blaming technology for the fact people live in the middle of nowhere (and agreed, in rapidly expanding areas).
If it were not for the RAM8 systems developed by Excetel (I'm pretty sure that's their name), an Australian company, many people would not have even had Dialup access in the bush. Loading coils and shocking cable runs are all too common in the country, and I have even had Communications Technicians request a service to go through a RAM8 to give better speeds for the internet. On top of this, the RAM8 has been a precurser to both ISDN boosters (BRA Boosters) and the Expandsl RU (remote unit). If you were to see all three units side by side, you would have great difficulty distinguishing the difference.
On top of this, CMUXs are essentially pair gains systems. Similar in some ways to integrated and non-integrated RIMs. Fibre from the exchange to the RU.
I suppose I am just having a bit of a rant about the BS I see flung around whirlpool constantly by both teenage game jockys and more mature internet jockys about Pair Gain Systems.
Dont forget, we live in one of the sparsest populated countries in the world. Running copper to EVERYONE would cost a too much. I am not defending the Big T, as I know how bad things can be coming from there. But dont forget, they are just a big company that is making profit, not a person that cares about their customers.
I live approx. 18km from another exchange that *is* ADSL enabled.
Does this new technology help me at all?
Thanks, Telstra...
What chances have i and the 20-50 other people in Ferndale got who are not only on pair-gains but on a Rim aswell.
We are atmost 6-8k's from the Exchange (15k's from perth CBD), but still can't get 256k let alone adsl2/+ .
Another version can be used to cheaply ADSL enable RIMs too, provided a spare E1 transport is available in the RIM.
Whether Telstra chooses to make use of these capabilities is anyone's guess.
If I understood the article correctly then the distance from the device to the user will have an unchanged limit. Let's say 4.5km. So does this mean that the backhaul can cover 15-4.5 km (or 20-4.5 km)? Is G.SHDSL that good? Or they are assuming multiple devices chained together every Y km? Or assuming 80dB attenuation limit? Or ADSL2 or ADSL2+ get greater distance?
Background: My exchange is ADSL-enabled but I'm 8 to 9 km (estimated wire) from it, so a simple 2 x 4.5km could still be marginal. But I have no idea what one might expect of G.SHDSL in terms of maximum distance.
2. Does "They can be upgraded to ADSL2 & ADSL2+ via a software upgrade." refer to upgrading the "customer side"?
The text is mentioned in the context of "Ethernet ports", which I assumed was referring to the backhaul, but it only really makes sense to me that the "ADSL2" is referring to the customer side.
3. How does the multiplexing work?
Is it completely transparent (please!)? They will be doing something horrid like NAT (which would prevent customers accepting inbound connections)? Tunnelling IP in IP? L2TP?
4. And just for grins, does it support link aggregation (channel bonding)?
If it turns out that this service is limited to 256kbps on the customer side (either due to distance on the customer side or due to congestion on the backhaul) or if it turns out that Telstra will only sell this when there are the full 8 potential customers ready to go, what if I want more than one link? (OK, so I'm desperate.)
The ADSL limit is the same as with any other DSLAM. Its the G.SHDSL backhaul that bridges the gap between exchange and the expandsl DSLAM.
A G.SHDSL backhaul can be made to cover those long distances and has been doing so for years with other products.
Your home could be ADSL enabled with this equipment by placing the expandsl device say 4km from your home, allowing the additional 5km to be bridged with the G.SHDSL backhaul.
2. Most modern DSLAMs (designed less than 3 years ago)can be upgraded to provide an ADSL2+ customer service. This one is unlikely to be any different.
3. Its transparent, no different to any other DSLAM service.
4. Any DSLAM can provide an aggregated service provided the ISP and you are setup for it. The DSLAM itself isnt aware of the aggregation.
5. The service speed you get should be no different to any other DSLAM, subject mainly to the distance between the device and you.
That still leaves me in the dark as to whether there is hope for me personally. But I would be waiting for the end of this trial anyway.
I queried the service speed on two grounds.
Firstly, if the G.SHDSL connection only provides a total 2.3Mbps *download* for 8 users and they sell those 8 users 1500/256 services they are overloading a lot more than if they sell those 8 users 256/64 services. I realize that all telcos choose an overloading ratio but some choose more appropriately than others. This seems to me a more constraining environment than would exist where the ADSL goes all the way back to the exchange.
Secondly, in trying to work out how the press release could come up with "20km" I was wondering whether they were simply including the assumption that the services would be limited to 256/64. But that's pure speculation on my part.
Is the 80dB attenuation limit that is currently being trialled, working to the assumption that the services will be limited to 256/64 or can they offer 1500/256 with the increased attenuation limit?
Does anyone know of readily available CPE that does it? I've seen multi-homed ADSL routers but I suspect that they aren't capable of combining the bandwidth intelligently i.e. only get bandwidth benefits (as distinct from availability benefits) if there are multiple concurrent active connections.
The technology is not rocket science, it has been around for many years in HDSL (2B1Q modulation) form.. G.SHDSL is preferred now as the X-talk means it can live with other xDSL flavours.
ADSL repeaters are not practical as they tend to make it difficult for other services to work in the same cable.
ACIF recommendations 9f & 9g limit the distance that G.SHDSL @2M can go to 1.9km or 2km. Of course the big T may get an exemption but that would allow the competitors to also get the exemption.....
So to go 10km before offering the somewhat truncated ADSL you may need 4 repeaters. Each repeater needing power. Only the first repeater can be line powered. Each repeater adds to the latency. Each repeater costs $$
While the idea has some merit the numbers ($) don't add up. High speed internet (>128k) for customers with long line lengths will always be compromised with xDSL. Fibre is the other solution but that also costs $$
I hope my ramblings make sense!
Anyway 2 weeks ago we recieved our password/username and our new modem in the post from Telstra this week.We followed the instructions loaded the software, connected up the ADSL modem and filters and guess what, it dont work,our phone works but now our old internet dialup speed is now a 26k connection instead of the usual 32k ,we rang the ADSL Broadband support centre 3 times they changed our password reconfiged our modem nothing ,still getting state down and a flashing orange/green apple,we have been informed that there is possibly a fault in the line or the exchange and will require a tech to have a look at it.Other people in the area also having problems connecting to our newly ADSL Broadband wired exchange.
I have been asking myself, Why would Telstra offer us ADSL Broadband,then process our application if it couldnt provide the service?, So they must have something in the works that can give us ADSL Broadband being 6.4kms from the exchange.As to whether we can get ADSL broadband well we will just have to wait until next week.
I personally think someone has made a big mistake because our lines are in such a bad state probaly 40 years old, we have had very bad line noise in the past, 6 months ago, so they installed a line amp and repaired all the conection points between us and the exchange,there are around 15 service connection points which are above ground which run through the middle of several propertys which cows rub against the poles and damage the lines requiring repair.
We have been lucky our phone line has been unaffected since it was last repaired and had a line amp fitted.The only problem now is they probally disconnected our line amp to give us ADSL Broadband which dosnt work and now we have a very slow dialup connection which makes banking or anything on the net a saga.
I have noticed that they have shrouded the phone line riser service posts out in the paddocks with PVC pipe recently, but I cant see how PVC pipe is going to stop a 600kg cow from using a phone line service post as a scratching post and expect it to provide 99% service reliabilty as mentioned under the ADSL broadband service agreement.Surely pits would make more sense but then again it would make them harder to find.
I would like to commend Telstra for trying its hardest to get ADSL Broadband into the bush but in the rush to get the numbers signed up before the new boys on the block step in, I think a better assement/upgrading of the existing cable infrastructure really needs to be done. I can see that if we do get connected to ADSL Broadband, it will be more headaches than what it will be worth.If I cant get a decent dialup connection whats to say Im going to get a decent ADSL Broadband service.Time will tell. In any event I will be pushing as hard as I can to make sure we get what we signed up for and wont accept no for an anwser.Meanwhile I'll just have to put up with the half service dialup.Thanks Telstra.
Not wearing rose coloured glasses anymore.
same like internet thru powerlines gaslines etc.
nowadays it's all wireless
wonder when Oz will follow
Who cares how old the technology is? For those of us in rural areas still waiting for *any* kind of broadband, the only thing that matters is the performance of the internet connection.
I'm more than happy to take a 1536/256 ADSL connection even if someone lucky enough to be close to an exchange that is ADSL2 enabled can get 8000 or if in downtown Tokyo, consumers measure bandwidth in megabits.
I'll take wireless if someone wants to offer it in my area. But I doubt that it will be.
Not laughing.
Wearing sun glasses the shine on this ADSL is a bit too bright for me.