Great discussion here, Frank & ahhaha. Permit me to offer some comments.
I didn't know that the DSC unit retained their name, tho.
I, too, was unfamiliar with the fact that ALA is marketing Litespan under the DSC name. ahhaha's reference to it is the first I've come across.
Litespans . . . they have been around for a while . . . The construction guys refer to them as "pair gain" No, not the company Pair Gain, but the engineering term which connotes the advantage of their use, as a function of ratio of virtual pairs that are gained through the use of multiplexing.
Your comments are reminiscent of my own introduction to this technology. First, as a frustrated surfer still surviving in the "dark" narrowband age, I was amazed to see several years ago technology such as Litespan and AFCI's UMC available "on the market" but not necessarily deployed in the field that would resolve real field issues such as extending DSL capabilities beyond the tariff limit of 18K ft. Obviously, DLC technology has come a long way since these products were first introduced, and as I alluded to in one post on LMT, the term DLC may not be the best way to describe the functionality of what these boxes can do today. Second, I myself, not coming from the telco industry, learned very early on the need to distinguish the term "pair gain" from the "PairGain," the company. Many telco field personnel I have spoke with at the time, did in-fact have the inclination to refer to "pair gain" as any system that enhances the capabilities of existing pairs previously deployed in the field. This caused obvious confusion for me as I was just beginning to learn the telco lingo.
The fact that the cable spans do not include copper often puts a crimp into the backup (disaster recovery) strategies of businesses who often request a certain number of their services be delivered over copper lines, all the way back to the central office. These are connected directly to the Class 5 switch and consequently survive ordinary power outages because of the central office battery and generator backup that is used to keep their switches operational during those periods.
Remote Powering
As I may have mentioned to you, the retired PB fellow, with whom I keep in contact, designed an onsite powered system for Universal Studios following the Northridge earthquake. Obviously, the issues you raise here highligh the necessity of this project. Accordingly PB was happy to oblige. Nevertheless, I think the power system my friend designed was more than the "remote fix" you subsequently describe.
Recommendation? The same as I recommended for powerline loss contingency for the proposed FTTH lifeline services: Take the copper lines if they're available --and use them for fax and modem dial up connection during normal times, just make sure you know where they are if you ever really need them for voice-- and keep your cellular/pcs phones charged.
As I understand it, SBC's Pronto will not be abandoning existing copper loops, but rather plan to utilize them much in the way you describe -- for lifeline services in the event of remote power outage. Pronto does not only including the laying of fiber & installation of neighbhorhood gateways at the RT, but also includes the laying of new copper to the cross-connect. I see the extension of this new copper serving two functions. First, the one you describe . . . abandoning the old loop from the RT to the cross-connect, thereby having a completely sustainable backup system to the cross connect in the event of remote power failure, thus ensuring voice lifeline services. Second, I can only suspect that the gauge of the new copper will be larger (in diameter, not gauge size) in order to fatten the copper pipe in order to ensure the fattest possible copper pipe over a given stretch to the cross-connect.
It is evident, IMHO, that SBC's strategy, or goal, is to wean ALL its customers onto DSL & off of POTS once VoDSL is provisioned in the field. By provisioning VoDSL, SBC will be able to completely remove non-digital customers from the old copper loops providing POTS. In this fashion, the old loops can be tweaked, whatever, to function only as the backup lifeline system you describe necessary in the event of remote power failure. |
