A Beginner's Guide to the Internet/INTERNET.ISO/text/telediag/tc13-099.txt

Text File | 1993-02-16 | 22.8 KB | 540 lines

TELECOM Digest     Tue, 16 Feb 93 01:32:00 CST    Volume 13 : Issue 99

Index To This Issue:                     Moderator: Patrick A. Townson

    Re: Cellular Phones Power Control (Gregory Youngblood)
    Re: Cellular Phones Power Control (Wilson Mohr)
    Re: PacBell IntraLATA Rate Ripoffs (Steve Forrette)
    Re: Pacific Bell, Caller ID, and PRIVATE (John Higdon)
    California Caller ID Blocking (Steve Forrette)
    Re: California Versus CLID Versus Out-of-State (David G. Lewis)
    Re: Hilton Hotel Telephone Surcharge (Steve Forrette)
    Re: Hilton Hotel Telephone Surcharge (Darren Ingram)
    Re: DS0 Portion of a T1 (Al Varney)
    Re: DS0 Portion of a T1 (Fred Goldstein)
    Re: Rochester Tel Wants to Split ([e-mail])
    Re: Bell Canada Charging For 411 (Charles Stephens)
    Re: Second Line Non-Pub/Unlisted? (Russ Kepler)
----------------------------------------------------------------------

Subject: Re: Cellular Phones Power Control
From: tcscs![e-mail] (Gregory Youngblood)
Reply-To: [e-mail]
Date: Mon, 15 Feb 93 11:11:34 CST
Organization: TCS Consulting Services


[e-mail] (Wilson Mohr) writes:

> This is true in most "small" systems. "small" meaning they have not
> got a large enough subscriber penetration to necessitate a system that
> utilizes frequency reuse.

This is only one reason.  I worked in several systems and frequently
had to disable cell sites power control features. Why?  Because of
terrain and foilage conditions which changed during the year resulting
in a large number of dropped calls.  By disabling this we were able to
get rid of that problem.  We had to disable the power stepping in both
directions.

While this wasn't the solution of choice, it worked, and we were
fortunate in that we didn't have to worry about reuse.


TCS Consulting Services   P.O. Box 600008   St. Paul, MN  55106-0008
      Mail-server requests to:  [e-mail]
[e-mail]        or       [e-mail]
 ...!srcsip!tcscs!zeta              or           ..!guppy!tcscs!zeta

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

From: [e-mail] (Wilson Mohr)
Date: 15 Feb 93 18:59:25 GMT
Subject: Re: Cellular Phones Power Control


[e-mail] (Wilson Mohr) irresponsibly writes:

> Portables by definition always run at (full) .6W...

Ooops. I have been corrected by my colleagues. That was the particular
implementation at a place I used to work. For correct information
please consult other postings in this group. Thanks!

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

From: [e-mail] (Steve Forrette)
Subject: Re: PacBell IntraLATA Rate Ripoffs
Date: 15 Feb 1993 18:53:54 GMT
Organization: Walker Richer & Quinn, Inc., Seattle, WA


In article <[e-mail]> John Higdon <john@zygot.
ati.com> writes:

> But what is the mechanism for offering intraLATA bypass? This CANNOT,
> repeat CANNOT be done via FGD ("1+" or "10XXX" dialing). Pac*Bell will
> not complete the call in this manner.

This IS possible for an enterprising long distance carrier to
implement.  They can take their version of the 700 number space and
use it for this purpose.  I believe there were stories of a company in
Illinois that offered this service.  Whenever you want to dial a long
distance intra-LATA call that your LEC won't give to a long distance
carrier, you dial it as 1 + 700 + number.  The carrier knows that when
it receives a call to the 700 NPA, the caller really means an
intra-LATA call within their own area code.  I guess this would only
work well in places where the local LATA is in a single area code
(which is the case for area code 916 where Execuline is located).  You
could even have a 'real' carrier as your PIC, then access the other
carrier via 10XXX for just intra-LATA toll calls.  I wonder why this
not more widespread.  Isn't AT&T the only carrier that is using 700
for another useful purpose?


Steve Forrette, [e-mail]

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

Date: Mon, 15 Feb 93 14:56 PST
From: [e-mail] (John Higdon)
Reply-To: John Higdon <[e-mail]>
Organization: Green Hills and Cows
Subject: Re: Pacific Bell, Caller ID, and PRIVATE


[e-mail] (Steven H. Lichter) writes:

> I would guess that if the return call is Toll or L/D it would appear
> as would any other one of that type.

Pacific Bell has stated that a return call that is toll will appear on
the bill with the last four digits converted to 'X's. Interestingly
enough, that is very useful information. If I suspect that some known
jerk in Hayward is calling me and I use "call return" on him and then
the bill shows up with the Hayward prefix of this person, it would be
strong circumstantial evidence of evil-doing.

Imagine if I actually found out who was annoying me on the telephone.
It drives the activists crazy to think that might be possible!


John Higdon  |   P. O. Box 7648   |   [phone]     |       FAX:
[e-mail] | San Jose, CA 95150 | 10288 0 700 FOR-A-MOO | [phone]


[Moderator's Note: If they blocked out the number with XXXX on my
bill, I would persist that since I was paying for the call, I was
entitled to know the number; then not pay for it until they revealed
it. I wonder how many write-offs they will tolerate from people who
take this stance regularly?   PAT]

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

Date: Mon, 15 Feb 93 22:07:41 -0800
From: Steve Forrette <[e-mail]>
Subject: California Caller ID Blocking


Regarding the Caller ID situation in California, I wanted to summarize
what I've seen in the past few Digest issues and offer some
observations.  Apparently Pacific Bell is now tagging all calls that
leave CA via an SS7- connected IXC as "private" so that call
recipients in other states see "private" on their Caller ID screens.
Although the CPUC has no jurisdiction to enforce this, Pacific Bell
has apparently done this in order to avoid a big stink that our
Socially Responsible friends would surely raise.

In any event, this creates a problem for those who do not receive
PRIVATE calls, either by subscribing to block blocking, or by not
answering calls that show up as PRIVATE on the Caller ID display.
This means that nobody from California can call them (at least using
an IXC that uses SS7 interfaces to the LEC on each end of the call).
Furthermore, it is not a good solution for Pacific Bell to just not
include the information, as this would prevent the other CLASS
features (such as Call Trace, Call Return, Call Screening, Selective
Call Forwarding, etc) from functioning.  And there currently is no
provision in the SS7 protocol to deliver the number with a 'partial
blocking' option to allow the NPA and possibly the prefix to be
displayed, but not the whole number.

Here are some technological solutions to the problem that I've thought
of (these are of course secondary to the ideal solution of Caller ID
being offered in California and/or Pacific Bell allowing out-of-state
delivery):

- Recipients could tell California callers in advance to call them on
a non-SS7 long distance carrier so that the call always shows as OUT
OF AREA.  Then the recipient can still protect their privacy by not
answering PRIVATE calls from the people who really want to call
anonymously.  A calling card call or operator assisted call is another
option ("Gee, I just can't get through when I dial myself, can you
try?")

- Recipients could subscribe to Priority Ringing and add their
frequent callers to the priority list.  Then, if a call comes in as
PRIVATE, but using the priority cadence, they recipient knows that it
is someone they really want to talk to.

- Callers from California could possibly use the unblocking code and
prepend calls with *67 to turn ON number delivery, when they call an
out-of-state person who refuses anonymous calls.  Is this allowed?  I
know that for over a year Pacific Bell has accepted the *67 dialing
code, even though it really didn't do anything.  Have all California
lines now been defaulted to "per-line blocking with per-call
unblocking?"  If so, this would be a much better interim solution that
the above two choices.  Can someone in California team up with a
Caller ID subsciber to test this?

These are just some thoughts from someone who thinks everyone should
be able to decide privacy issues for themselves, either by using

Caller ID for incoming calls, or blocking for outgoing calls, without
having an outside force or special interest group make the decisions
for them.


Steve Forrette, [e-mail]

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

From: [e-mail] (david.g.lewis)
Subject: Re: California Versus CLID Versus Out-of-State
Organization: AT&T
Date: Mon, 15 Feb 1993 21:39:57 GMT


In article <[e-mail]> [e-mail] (Ken
Dykes) writes:

> In Telecom-Digest: Volume 13, Issue 76, Message 10 of 16:

>> live in southern Ontario CANADA.  My Caller-ID box instead of showing
>> out-of-area showed PRIVACY.  The call to me was made (and answered)
>> twice in the same night; both times PRIVACY ... some sort of
>> call-blocking was enabled by PacBell.

> Also, *can* California residents enter the blocking code even though
> Caller-ID as a service doesnt exist? Seems unlikely.

> [Moderator's Note: Yes, people in California -- at least in the Bay
> Area and San Jose -- *can* enter the privacy *67 code. Tests have been
> done to demonstrate this. JH has done it, and gets the three spurts of
> tone in response, for whatever good it does.

"For whatever good it does" indeed; the confirmation tone doesn't
*necessarily* mean that the request has been acted upon, although it
may.

> And get this: I've gotten calls from the Bay Area which show up on
> my display as 'outside' one time, and 'private' the next ... from the
> same caller! PacBell is doing something with the ID, that's for sure.
> *What* they are doing is not clear yet.

The behavior above is consistent with the hypothesis that PacBell is
indicating "presentation restricted" on all calls going to an IXC via
SS7.  It is possible for two consecutive calls from the same calling
station to the same called station to take different routes through
the network.  For one thing, the caller may have indicated a different
IXC, and the IXCs may be at different stages in SS7 Network
Interconnect deployment.

If the same IXC is used, different paths may have been used from the
EO to an Access Tandem due to overflow off a "High Use" group to an
alternate trunk group, where the signaling may be different on the two
TGs (SS7 in one case, MF in the other).  Or, one call may direct route
to the IXC from the End Office via MF trunks, and the other may route
from the EO to an AT via SS7 trunks and from the AT to the IXC via SS7
NI trunks, again because of overflow.  Or the SS7 NI trunks may be at
the EO, and the MF signaling may be on the EO/AT trunks.

Even if all calls from a given EO to a given IXC are directly routed,
not all trunk groups will be cut over to SS7 at the same time, so one
call may be routed over an SS7 signaled trunk and another call routed
over an MF signaled trunk.  In any of these cases, the call with
end-to-end SS7 will result in "Private" being displayed, and the call
with an MF signaled trunk somewhere in the path will result in "Out of
area" being displayed.

Disclaimer: I don't work on NI deployment.


David G Lewis                              AT&T Bell Laboratories
[e-mail] or !att!goofy!deej     Switching & ISDN Implementation

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

From: [e-mail] (Steve Forrette)
Subject: Re: Hilton Hotel Telephone Surcharge
Date: 15 Feb 1993 18:32:38 GMT
Organization: Walker Richer & Quinn, Inc., Seattle, WA


I've found an effective way to get around the policy at hotels which
charge a surcharge for 800 'calling card' access numbers, but not for
'regular' 800 numbers: get a calling card from one of the 'third
banana' carriers.  I have one from ITT/Metromedia which I use in
various special circumstances, and I have yet to find a hotel which
recognized its 800 number as a 'calling card' 800 number.  The card
also has no per-call surcharge of its own, so I can place a short long
distance call from a hotel without paying a king's ransom.


Steve Forrette, [e-mail]

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

Date: Mon, 15 Feb 93 07:48:12 GMT
From: [e-mail] (Darren Ingram)
Subject: Re: Hilton Hotel Telephone Surcharge


At the Hilton National hotel in Wembley, North London, the in-room
phones charged 30 pence (100p=$1.43) per charging unit, which is the
same as a standard 5 pence (well 4.9x pence) BT charge unit.


Darren
DIMS (newsdesk mailbox)([e-mail])   - Views expressed do  -
184 Brookside Avenue, Whoberley, Coventry CV5 8AD UK - not automatically   -
Tel:[phone]/Fax:[phone]/Tlx 94026650 - represent those of  -
*News, features, PR, consultancy & network services* - DIMS or its clients -

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

Date: Mon, 15 Feb 93 23:46:20 CST
From: [e-mail]
Subject: Re: DS0 Portion of a T1
Organization: AT&T Network Systems, Lisle, IL


In article <[e-mail]> ddssuprs![e-mail]
(Fred R Stearns) writes:

> How is the A/D and D/A conversion performed to create the digital data
> from and analog voice circuit to the 1/24 digital circuits of a T1
> service?  Is it CVSD, or seven-bit samples at 8KHz, or something else?

   You need a reference on mu-law or A-law PCM encoding, or something
that explains analog-digital CODECs (coder/decoders).  Try almost any
good book on digital transmission systems.  CCITT recommendation G.711
covers A-law and mu-law encoding (aka "the Blue Books").

   {Proceedings of IEEE}, Vol. 62, May 1974 contains an article called
"Digital coding of speech waveforms: PCM, DPCM and DM quantizers".  Or
try the horses mouth: "The T1 Carrier System", {Bell System Technical
Journal}, Vol. 44, No. 7, Sept. 1965.

   Very briefly, a CODEC works through the following steps:

a) a low-pass FILTER limits the signal to about 3.3kHz and virtually
   no signal > 4kHz (per Nyquist).

b) a SAMPLER takes a "snapshot" of the instantaneous voltage 8000
   times per second.

c) while the SAMPLER holds a particular "snapshot", a QUANTIZER converts
   the analog voltage to a digital representation of the measured voltage,
   a value between 0 and N ( >256 values).

d) The digital representation is mapped by an ENCODER into one of 256
   values (some values may not be used).


   This 8-bit value is one channel of a DS1/T1 signal.  Since the
samples are at 8000/second and are 8-bit units, you get 64000
bits/second for each voice channel.  Various transmission systems can
alter the low bit in each 6th sample for their own use (bit robbing),
thus giving "almost 8-bit voice".  When these signals run through
various switches, more samples can be "robbed" as they are switched
onto other transmission facilities.  If you are VERY un-lucky, you can
get an effective rate of 7 bits/sample.

   The A-law and mu-law encodings are just different forms of
converting various points of input voltage into a non-linear digital
representation.  Both use a multi-segment approximation to a
logarithmic curve, so that small variations of small voltage levels
receive different representations, and larger variations of larger
voltage levels are needed before the sample is assigned a new value.
This is called "companding", and attempts to offer a constant
signal/distortion ratio for normal speech signals.

   The receiving end, a DECODER converts the 8-bit values back to
their original "snapshot" values and then uses a low-pass
"reconstruction" filter to convert (almost) back to the analog signal.

   Real implementations can interchange steps c) and d), using a
non-linear analog COMPRESSOR to modify the "snapshots" into the
non-linear "companding" curve and then a linear QUANTIZER.


Al Varney

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

From: [e-mail] (Fred Goldstein [k1io; FN42jk])
Subject: Re: DS0 Portion of a T1
Reply-To: [e-mail] (Fred Goldstein [k1io; FN42jk])
Organization: Digital Equipment Corp., Littleton MA USA
Date: Mon, 15 Feb 1993 21:22:53 GMT



In article <[e-mail]>, ddssuprs![e-mail]
(Fred R Stearns) writes:

> How is the A/D and D/A conversion performed to create the digital data
> from and analog voice circuit to the 1/24 digital circuits of a T1
> service?  Is it CVSD, or seven-bit samples at 8KHz, or something else?

The standard method is Pulse Code Modulation (PCM), with 8000 samples
per second and 8 bits transmitted per sample.

In North America, the low order bit is sometimes "robbed" for
signaling, (1/6 of the time) which limits data to 56 kbps.  In North
America, a 12-bit linear sample is compressed to 8 bits via a formula
called mu-255 (note News won't pass Greek letters), while Europe
compresses it using a formula called "A law".  Europe also inverts
alternate bits.  So the two flavors of PCM are incompatible.

Of course, some long-haul transmission systems use lower bit rate
audio, like ADPCM.


Fred R. Goldstein   [e-mail]
k1io             or [e-mail]   voice:[phone]
Standard Disclaimer:  Opinions are mine alone; sharing requires permission.

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

Date: Mon, 15 Feb 93 13:13:04 EST
From: [e-mail]
Subject: Re: Rochester Tel Wants to Split


[e-mail] writes:

> Whereas regulation provides at least some tie-in between the cost of
> providing service and the pricing of that service, the proposed
> solution will most likely result in offerings that tie prices to a
> perception of value.

But regulation is always imperfect, and will allow value-based pricing
to some extent.  A monopoly will always push for higher (value-based)
prices, and regulators will invariably allow some such pricing.

If the regulators are one step removed from setting the actual retail
phone rates, they may be in a better (political) position to set
cost-based rates for the 'wholesale' services the regulated network
vendor will provide.

If there is indeed cost-based pricing for the regulated network
services, and if there is substantial competition among retail
telephone service providers, then value-based pricing cannot prevail.
As much as a provider would like to impose value-based pricing, it
would be quickly undercut by its competitors if it attempted such a
scheme.

> Simply put, for the residential user, flat-rate telephone service is
> likely to be priced substantially higher than it is now, because
> there will be some significant portion of customers for whom
> flat-rate service will still be a better *value*, even at a much
> higher price.

Only if the current flat-rate service is now priced below cost.  A
provider could get away with pricing substantially above cost only if:

 - there isn't any viable competition, or
 - it provides added value that its competitors do not.

Hopefully, the restructuring can be done so that a healthy competition
among telephone service providers ensues.  If a provider can give such
valuable service that customers are willing to pay extra, I say:
Hurrah!

Also, a hotly competitive environment will be more likely to produce
rational pricing schemes, such as the (peak-hour measured)/(off-hour
flat-rate) scheme which has been mentioned here before.  I venture to
guess that such a scheme might be cheaper than the current residential
flat-rate plans.

If properly structured, the Rochester Tel transformation could be a
model for the rest of the country, and could usher in an era of
plummeting local phone rates, similar to the precipitous fall in
long-distance rates we have seen in the past decade.  (Indeed, it
might produce still lower long-distance rates: a competitive local
telephone service provider might rebate some of its share of the
long-distance access charge, to attract more subscribers.)

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

From: [e-mail] (Charles Stephens)
Subject: Re: Bell Canada Charging For 411
Organization: COW Pastures
Date: Mon, 15 Feb 1993 17:22:00 GMT


Tony Pelliccio ([e-mail]) wrote:

> In most parts of the US it's a fact of life. You're allowed roughly
> five free calls, and then after that it's around 25 cents a pop.

> Besides, that's why you get a directory every year ... so YOU can look
> it up. Now they've given you an incentive. :)

Well Southern Bell only gives you three freebies before they charge
you US$.30!!!

But, with more phone lines you get more free DA calls.  With my three
phone lines, I get a total of nine free DA calls (of course I usually
make about 15-20 calls a billing cycle).

I would use the phone book, but not only are they inaccurate, they get
destroyed pretty quick.


Charles Stephens     [e-mail]

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

From: [e-mail] (Russ Kepler)
Subject: Re: Second Line Non-Pub/Unlisted?
Date: 15 Feb 93 18:28:09 GMT
Organization: BASIS International, Ltd., Albuquerque NM USA


In article <[e-mail]> [e-mail]
(Paul Barnett) writes:

> A current resident of Mpls-St. Paul has informed me that US West is
> not currently charging him for a non-published second line.  I wonder
> if this was always the case, and it was a matter of convincing whoever
> answered your call to customer service that day.

When I was told that I'd have to pay for not listing the modem line to
my house I simply started musing about possible names: "Freddy
Phudpucker", "Telco Ripoff", "Ma Bellsux" etc.  The service folks got
the idea, and simply gave me the line unpublished.  It could be that
they were tired of me already -- it had been a tiresome series of
their diconnecting one of two lines, one with a forward to the new,
etc.  I got on a first name basis with some of the service reps ...

The modem line still has some trouble in the billing system -- I pay
for the second line on my regular bill but still get occasional calls
from the telco -- one asked where the LD was to be billed, and another
asked where the line itself was billed.  They were lucky that I even
answered the line -- the modem doesn't and U usually don't, but after
40-50 rings I'll answer and that about how long it took.

I have a suspicion that they have some sort of rule that allows them
to reject an obscene name, but they'd have some real trouble rejecting
a line that simply insulted their "service".


Russ Kepler, Basis International Ltd. [e-mail]  phone: [phone]

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

End of TELECOM Digest V13 #99
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