_________ SWAT MAGAZINE ISSUE FIFTEEN: MARCH 1999 __________ / \___________________________________________/ \ / Fone Technologies Of The New Millenium \ / By =The-Doh-Boy= \ ----------------------------------------------------------------------- Pretty snappy title huh.. Well In this article I hope to focus on technologies which are yet to make their way to the end user. I'll be taking the point of view of a phreaker who wants to know the possible loopholes of the taechnologies. Wavelength Division Multiplexing. A really great technology which could cut the cost of calling pretty much 100%. Everyday multiplexing is done using the TDM (Time Division Multiplexing) technique. This technique allows Multiple subscriber to subscriber calls to utilise the same trunk lines. An illustartion to show how this works follows: -Call 1: (First in line) ------------ -Call 2: (second in line)------------------- Single trunk line holding *1* call at any time -Call 3: (Third in line)------------- Realistically the line numbers would not have a one to one correspondence with their order in the queue.This would be allocated using an algorithm stored on switching equipment. The usage of the network is never 100% and so the loss in quality of the calls is *very* minimal. As one can see this method will have its problems. There is an upper bound on the call capacity set by the sampling rate of the sound levels at the subscribers fone and the number of subscribers using the line at any one time. The upper limit varies directly (assuming that the number of callers at the peak is roughly constant) as the sampling rate. One way to overcome this is to use seperate wavelengths for seperate calls (or TDM lines). This means that each WDM line can carry a multiple of the equivalent TDM lines. This means the cost to the end user should vary directly as the cost of TDM and inversely as the equivalent number of TDM lines per WDM line. Local calls (in the UK) are already 1p per minute for a standard line so even a small WDM/TDM ratio could see calls becoming *extremely* cheap. The fone will become just another utility which can be left on all day (much as electricity is now). There are two main pitfalls which I can think of about this technology. Firstly there is the problem of interference from other calls. This effect will be much the same as radio interference causing call quality to drop. A possible solution would be to allocate wavelengths based on prime numbers. These would not be harmonics of any other signal in the wire, stopping interference almost completely. Phases can be allocated randomly also to prevent interference. Another is the limited spectrum available. Due to the photo electric effect most of the signals will have to be sent (along fibre optic cable) at a wavelength particular to the materials used in the detectors. If digitally encoded, the transfer rate (although HUGE) will be limited by the switching times of the semiconductor equipment at the other end. An advantage for the telcos is that conference call facilities can be made just by "tuning" three calls into one wavelength on a specific line. No doubt this could be taken advantage of to listen on others conversation or step up trunks e.t.c. I would expect also that inter-office signalling would travel on the same lines as consumer calls. Perhaps if telcos are thick enough to put them at the lower end (where the density of calls is greater) these can be "tapped" by phreaks. I think that covers most of what phreaks need to know about WDM. Telefony Over The National Grid. Another high bandwidth technology (which may even incorporate the above system) which can see the cost of calling drop. I doubt this will ever get off the ground personally. BT/AT+T will see their profits at risk and will try anything to stop this technology taking hold. Basically how this works is to sned signals over the electric distribution system. A pretty good idea, especially as the system can provide high bandwidth on a system already present in peoples homes. One obvious advantage to telcos invoived would be that it would stop beige boxers :> (clip clip, ring ring, fry fry!!!!) Up to subscriber level the system is bound to be similar to the structure of the PSTN system, i.e. sub-units acting as exchanges e.t.c. At subscriber level the network will assume a star topology. IP Telefony. Notable in that its already in existence. To check out a good example go to www.net2phone.com and download the software. That gives you 1-800 access and a complimentary bundle of minutes. This is the use of the internet to conduct voice telefony. It can be thought of as a gateway between the internet and the PSTN (although some applications of this only go net-net) This makes calling intenational as cheap as a local call to your ISP so that cant be bad. Things like NetMeeting and Netscape Conference/Cooltalk are already in use and are free to use. BT already feels threatened and is ploughing alot of money into this technology in order to save it market share. As for call quality I think its about as good as a digital mobile driving down the M1 at 100mph in that the volume varies considerably. This is due to the packet technology in use on the net. Good news for hackers is that the servers can probably be hacked and used to route calls through. Also, AT+T are providing an IP Conference call system (Free for ten minutes during the Superbowl) This will allow you to put in numbers, and then call them all at once using your computer. Check around on the net for such things, they are growing steadily!!! Videoconferencing. Aaaahh.....Takes me back to when I was at a BT exhibition in 96/97 when they had their videofones on display. Of course they had two set up to allow two people to talk on them. What they forgot was that if you hung up you could dial out on them. So if BT can be that stupid well who knows! nyhoo back to videofones. Businesses are increasingly using these as it provides an ideal solution to the problems of teleconferencing. i.e. talking over someone else. No doubt as the service expands in bandwidth perhaps TV and the net may integrate into this service, providing a one stop comms shop as it were. No doubt BT would charge a premium for this kind of thing!!! GPS Cellfones Dangerous technology for the phreaker if this becomes defacto. Think of the ability of an operator being able to trace not only your number but *exactly* where you are!!! Very bad stuff. Free Local Calls In The UK Finally in 2000 (approx. when OFTEL takes the restrictions from BT) we can take a leaf from the book of our American phriends and learn how to step up trunks and so on. Local PBX hacking will become normal and the appeal of Meridian Systems may wane slightly. Perhaps a way can be found to busy out certain routes and make the switching systems hand you off up the trunk, a few key presses later and you can make a free call anywhere!!! The weak link there is trying to block certain paths through the system. I'm looking forward to this (he says rubbing his hands together) That wraps up my brief run down of future technologies I think will concern the phreak in the future c'ya..................................................................