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Topic Title: Data networks; Fixed and Mobile, how ready are they?
Topic Summary: What big technologies will future-proof the worlds' data infrastructures?
Created On: 03 February 2011 09:27 PM
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 03 February 2011 09:27 PM
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Avatar for CharlesJEdwards                                   .
CharlesJEdwards

Posts: 6
Joined: 25 July 2008

I am researching the current state of data networks, particularly the backbone for these networks across the globe. My interest is both in the mobile and fixed infrastructures.
Users of these services are being offered bandwidth hungry content, more users are being added all the time, the expectations for speed are constantly increasing and the means of accessing the content are diversifying.
What technologies are being rolled out to cater for these demands, both current and future? Will future networks be able to cope with these demands?
 15 February 2011 01:11 PM
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gtuteja

Posts: 9
Joined: 16 March 2002

As of now Fibreoptic backhaul networks are capable of offering vast bandwidth. DWDM technology is alrady mature and is deployed worldwide. Access nteworks are limited both in wireless as well as Wireless. Though 5G & LTE appear to be promising of delivering large bandwidths but eventually Fibres ahve to be deployed in access as well.

G S Tuteja

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gtuteja
 15 February 2011 09:41 PM
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Avatar for CharlesJEdwards                                   .
CharlesJEdwards

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Thanks Gurmeet for your comments.
It is true that the future for backbones in both fixed and wireless is secured with fibre but surely the answer with fibre is not to just simply lay more fibre pipes as many operators are doing around the globe. DWDM has established itself but what comes after that; new materials for fibre, modulation schemes, detection equipment, routers etc, is an AON (All Optical Network) a reality now or when will it be a reality.
The data being transmitted across these networks, in what form will it be, currently moving towards IP but is this efficient? How will networks be arranged and managed in the future, how will QoS be implemented?
On the wireless side, yes, LTE and IMT-advanced do provide an excellent roadmap but will 1Gbps be sufficient when it is eventually rolled out and how will we manage the crammed spectrum? WIFI networks are proving too tempting for mobile operators to use for data offload, how many WIFI networks will they be able to deploy before that area of spectrum becomes swamped, Cognitive Radio Networks could help out but we need to determine whether or not this is viable.

It would be great to have see views people may have on the issues mentioned.
 16 February 2011 01:08 PM
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backinuk

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Hi
Broadband over power line (BPL) and power line transmission (PLT)is a means of transmission they have decide to use and my understanding is that BT are rolling it out as well as several other countries.
"All good "you might say using existing wiring and infrastructure to get internet to the masses; However EMC regulations would appear to be being infringed on here with this product.
If the use of this product is causing interference to other users of the radio spectrum, and there seems to be plenty of evidence supporting this theory, is this a good thing to be rolling out?

http://www.bbc.co.uk/rd/public...s/whitepaper067.shtml
This is a link to a white paper testing the effects of power line telecommunications on broadcast reception, invited by Scottish and Southern Electricity
I have been following the amateur radio fraternity with interest as well and they have taken the issue to Ofcom and are still in dispute regarding the issue.
It would seem with regards to the EMC implications that OFCOM are saying that it can't be the PLTs it must be other equipment not complying.

To me it just seems like another money driven scheme much like the DAB fiasco when DRM would have been much better..........................
 21 February 2011 12:58 PM
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ectophile

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As a BT Broadband customer, I haven't heard of BT running broadband to the home by power lines - as they are a telephone company, I can't see why they would want to.

However, they have supplied large number of ethernet-over-power connectors for the BT Vision service. These use the home wiring as an alternative to running additional ethernet cables around the home.

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S P Barker BSc PhD MIET
 21 February 2011 01:17 PM
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backinuk

Posts: 24
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Sorry I was trying to be brief with the post, I was hoping that engineers reading would have taken the essence of what I was trying to highlight and done their own research into the subjet raised.
Thanks for clearing up any ambiguity.

--------------------------------------------

Michael Moore
Engtech, ICTTech, JIB Approved Electrician
 26 February 2011 02:32 PM
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CharlesJEdwards

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Regarding BPL and PLT.
It is interesting that OFCOM have taken the stance that the interference must be from other sources, spurious radiation from powerlines has always been a problem though. Surely there must be a consequence of placing additional high powered frequencies(for data comms) down such a line.
PLT has been in use by energy companies (for their own internal comms) for many years but I would guess BPL is a more recent obvious spin-off from this.
Almost all homes in the UK will have electricity, so it would make sense for BT to piggy-back on these lines to provision broadband to the rural areas.
This technology has its place but I don't think it would possible to build the large "data pipes" required for the future using power lines.

Optical networks will provide the massive "data pipes" and infrastructure for future fixed-line and core networks. I am very interested in thecurrent state of optical networks, the progress of All-Optical-Networks and the emerging optical modulation schemes.
 28 February 2011 02:50 PM
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backinuk

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Regarding "the current state of optical networks" I read this dated white paper "Next Generation Multi-Service Optical Networks"
however it gives a good account of where we are today.
http://cavendish.homedns.org/cavendishNGTransport.pdf


This will help with optical modulation schemes, "Optical Modulation for High Bit Rate Transport Technologies" I understand that the Amatuer radio group helped to develop PSK

http://www.sunrisetelecom.com/...ptical_Modulation.pdf



With regards to " the progress of All-Optical-Networks and the emerging optical modulation schemes. "
I understand that the first Quantum computer has been made and undergoing trials. Could this be the shape of things to come?
At about 25mins into the video you will see the Quantum computer
http://www.bbc.co.uk/iplayer/e...2011_What_Is_Reality/#

Edited: 01 March 2011 at 04:31 AM by backinuk
 01 March 2011 10:06 AM
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gtuteja

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Dear Charles

Even as of now with DWDM huge capacities are available as size of Fibre optic cables has also grown from 12 Fibres to 96 Fibres.

All optical networks are already a reality but not in a big way. Lot of developments are underway in the field of All optical Switches, Routers, Optical Add/Drop Multiplexers etc.Hence deployment of all optical Networks is expected to gorw substantially in near future. Lot of research is underway in new materials.
LTE & IMT promise upto 1GB delivery but definitely spectrum availability would become a constraint.

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gtuteja
 01 March 2011 11:01 AM
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IanDarney

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Broadband over Power Lines

Interference due to Broadband over Power Lines (BPL) has been a subject of increasing concern to the EMC community over the past few years. In July 2009 the editor of the EMC Journal was led to write: 'It may provide a cheap method of watching TV over Broadband and connecting other digital equipment but it has some very serious interference pitfalls. Despite these shortcomings, the EU (apparently supported by the UK government) have treated with contempt the legitimate complaints from some very respected organisations NATO, BBC, ERA Technology & York University plus many in Europe': www.theemcjournal.com

As I understand it, BPL utilises the common-mode loops in each house. Current flows via the parallel combination of live and neutral, returning via the earth conductor. Transformer coupling is used to inject a voltage into the loop at one location and to monitor the current at another. Interference is due to the fact that the house wiring acts as an aerial. Not only that, the power supply to the house provides an excellent path for current to flow into the wider environment.

It may be possible to inhibit that extra flow into the environment by installing transformer-coupled resistors at the switchboard. This would effectively block outgoing and incoming radio-frequency signals, as well as attenuating switching transients. The concept of absorbing unwanted electromagnetic energy is described in section 8.6 of 'Circuit Modelling for EMC' ( www.designemc.info ">http://www.designemc.info ). Has anyone used this approach to ameliorate BPL interference?

Ian Darney
 12 March 2011 04:29 PM
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Avatar for CharlesJEdwards                                   .
CharlesJEdwards

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Hi Gurmeet,
You mention that the number of fibres in a cable has grown to 96, could you possibly elaborate on this, where would these cables typically be deployed?

There will need to be much more investment in A-O-N's but will this be public of private money...

Regarding spectrum availability, the specifications for LTE allow the use of a number of bands over quite a large range, this makes it very flexible making use of licensed spectrum wherever it is available but does cause a headache for designers.

Regarding spectrum availability, I have started a separate thread titled "Cognitive Radio Networks", this could provide a solution and buy some more time.
-C
 14 March 2011 05:02 PM
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haguetim

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Re PLA

You put RF onto an unbalanced unshielded line it will radiate.. period, The proponents of power line technology cannot re write the laws of physics.. It is not fit for purpose.
The latest wide band chipsets from gigle also interfere with DAB and produce interference across the aeronautical bands.
 09 April 2011 07:09 AM
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gtuteja

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Dear Charles

Traditionally Optical Fibre cables having 24/48 Fibres have been deployed in Backbone network, whereas Cables having 96 fibres wold be deployed in Intra city network and for broadband delivery to subscibers via Fiber to kerb, Fibre to The Home.

Incumbent operator (private or Public) by virtue of having in place a robust Copper cable are deploying the same for delivery of broadband using XDSL technologies.

New opeartotrs are trying different models such as use of Cable TV infra structure and also investing in Optcal Fibre infrastructure. Hence to fully exploit Optical Fibre capabilities Opeartors will ahve to invest in All optical Networks as well whether they are public or private


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gtuteja
 22 April 2011 05:29 AM
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TomThomson

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A couple of people seem to think that the Ofcom position on PLT is that it isn't causing interference. They have an alternate position to that one: that they have no powers because the PLT kit isn't a transmitter (just as OFCOM don't regulate or police electric motors with inadequate radiation suppression, they don't regulate or police this stuff either). We seem to be in a position where those that are responsible for this are pulling hard to get the rules changed to make levels of emission that are cuirrently forbidden by the regulations into allowed levels, and putting together dummy solutions to the problems which while they may work under lab conditions (although even that is by no means certain) almost certainly wont work in the wild.

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Eur Ing Tom Thomson MA MSc MBCS CITP CMath FIMA CEng FIET
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