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Re: [EFM] EFM Requirements

     Dear Sherman, first of all thank you for your inputs on the possible 
     requirements for EFMC.
     Actually, I have two concerns.
     The first one concerns your penetration scenario. I thought that EFMC 
     was targeted primarily (but not exclusively) for MDU/MTU market which 
     de facto means EFMC systems will be deployed in urban areas with a lot 
     of home/office buildings, high density of population and relatively 
     short ditances from distribution points to end customers (some surveys 
     said in between 500 to 2000 feet in most of big cities worldwide).
     Your figures (i.e., 100 households reached in a perimeter of 3 km) 
     seem to be far more pessimistic.
     I think that to help in defining what could be the optimal reach and 
     bit-rates for EFMC, it would be interesting to first identify the key 
     market segments: i.e., MxU, FTTB + EFMC, others and then to collect 
     some recent figures on the percentage of people reached (penetration) 
     in the case of these different deployement scenarios with figures on 
     the current situation and on the forecast.
     Some old statistics for US only (from two surveys by Telcordia 
     technologies : 1983 and 1990 ) were presented at the EFMC meeting in 
     May 2001. I think this could be a good starting point and we should 
     maybe try to update these figures and extend the survey to other 
     countries in the world.
     I think that having the support and the help from telcos, regulatory 
     bodies, independant auditors would facilitate the work.
     Having a clear picture on the type of deployment scenarios and on the 
     targeted applications could be of great help to define requirements 
     for EFMC (e.g. in terms of reach, bit-rates, network topology).

     My second concerns is about HPNA. I don't understand clearly the 
     coexistence issue with HPNA.
     For me, there are two possible scenarios
     1- the EFMC system is placed at the entry point of the household like 
     a gateway (in that case it is connected to local server or the central 
     distribution point outside). Then, inside the house, data distribution 
     is ensured by HPNA. In that case, one just have to implement a simple 
     passive filter at the EFMC gateway to isolate the Home network from 
     I would even say that it shall be mandatory to do so otherwise
     your HPNA could be uncontrolable and disturb a lot the outside world 
     which will never be tolerated neither by telcos nor by service providers.
     For information at the Geneva ITU meeting in February, Telecom Italia
     raised this problem of HPNA isolation.
     2- Your home/office network is a LAN or a point-to-multipoint EFMC network 
     (i.e. a set of EFMC-PHYs connected together) . 
     In that case, there is no need for in-house/in-building distribution 
     through HPNA and so pb of coexistence with HPNA is avoided.

    Many thx in advance for your feedbacks.

    Very best regards
    Christophe Del-Toso, STMicroelectronics

______________________________ Reply Separator _________________________________
Subject: [EFM] EFM Requirements
Author:  SAckley (SAckley@xxxxxxxx) at internet
Date:    8/13/01 5:31 PM

Service Provider Requirements for Ethernet in the First (two) Mile(s): 
Sherman L. Ackley, CTO
The National Rural Telecommunications Cooperative provides services to over 
350 member independent telephone companies who serve over 6 million access 
lines.  Ethernet in the first mile is the most promising technology for the 
delivery of integrated voice, video and data services in the suburban and 
rural areas served by our Members.  As the Chief Technology Officer for 
NRTC, I would like to submit some practical requirements as seen by the 
service providers most likely to implement this technology in the USA.  The 
intent of this contribution is to help the study group prepare the 
requirements document based on actual needs.
The user locations will be 90 percent residential and 10 percent business. 
Of those businesses, 90 percent will have 10 or fewer PCs.
The system must work over standard high capacitance telephone outside plant 
cable.  Binder group integrity is not assured.  The technology should not 
force removal of bridge taps and end sections.  It needs to operate without 
degradation at binder group fills over 70%.
System reach is the most important aspect of the design.  Ethernet in the 
first mile must operate over the longest reach possible.  The number of 
households and small businesses served by a node is proportional to the 
square of the reach.  For example, a reach of 3 km can serve about 100 
single-family homes per node. Doubling the reach to 6 km increases the homes 
served per node to 400.  And with a 12 km reach, 1600 homes per node can be 
served.  This assumes 100 percent subscribe.  At 25 percent subscription, 
short reach technology gets down to some dismal financial outlooks in terms 
of cost per revenue producing subscriber as well forcing the construction of 
too many street corner server nodes.
Coexistence with HomePNA on the same cable pair is essential.  This feature 
will be necessary in over 75% of households served with Integrated Broadband 
services.  For example, a data stream of 10 Mbps will support two MPEG-2 
high-resolution standard TV signals.  The DSL will carry this to the primary 
service set-top box/home gateway that can be located anywhere in the house. 
The Gateway device will terminate the video and data for use at the primary 
TV, it will then forward the second video and data over the same cable pair 
to other set-top boxes and PCs within the house using HomePNA.
Peer-to Peer (or server to server) communications requires that the service 
be adaptable so that full rate is available upstream or downstream as 
required by the user generated traffic.  For example, it is now possible to 
record MPEG-1 video on a camcorder and e-mail it over the Internet. 
Unfortunately, sending the e-mail over a conventional fixed data rate 
ADSL/VDSL system takes forever for the 20 Mbps file.
There is little demand for sending three simultaneous MPEG-2 video streams 
to the home.  This is based on the analysis of over 20 million DBS and 
digital cable subscribers.  In fact, two streams are required in only 30 
percent of households.  It is far more economical to install a second 
Ethernet Subscriber Loop (ESL) for the one in 100 who want three HDTV videos 
than to burden all with the high costs required to support a higher bit rate 
short reach technology such as VDSL.
In conclusion, long reach is of paramount importance.  For delivery of two 
Standard TV signals, 10 Mbps at 12 km is required.  For one HDTV plus one 
Standard TV, 20 Mbps at 12 km is desired.  Also, the selected technology 
should allow data to flow in either direction at the full data rate. 
Finally, the technology should be spectrally compatible with HomePNA without 
requiring the use of a splitter at the residence.
Finally, feedback on these ideas from other service providers and vendors is