POTS line barely supports 2 REN

I suppose this is one problem where the phone company line people will blame your equipment without doing the necessary tests on the line. You'd expect a POTS line should be able to support 5 REN. AC power induced on the POTS line can mess up the ringing signal especially if there's a significant longitudinal imbalance. But Verizon just trains their techs to blame the CPE and go away. Besides adding to the technical details of the problem and possible solutions, how about providing some hints about how to deal with the phone company to fix their problem?

Reply to
MCO
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I always have genuine WECO 2500 sets around. If they claim your equipment is FUBAR, you can wack 'em over the head with same...

File a PSC/FCC complaint.

Reply to
David Lesher

Probably all true, but how do you measure the 2 REN you claim you are getting?

Is your place in an apartment house or a single family house?

Reply to
Rick Merrill

----- Original Message ----- From: "Rick Merrill" Newsgroups: comp.dcom.telecom.tech Sent: Friday, July 28, 2006 9:46 AM Subject: Re: POTS line barely supports 2 REN

This is a single family house. The load I'm putting is 1.0 B, 0.1 B, and 0.7 B and 0.1 A. I add a modem rated 0.1 A (or a standard WECO set at 1.0 A) and I get no ringing. There's 100+ volts AC voltage tip to ring on the isolated POTS line while idle. Ring to ground is also 100+ volts while tip to ground is around 10 volts. This is a cheap digital voltmeter, so I don't know how it handles the DC component on the line (-45.6 volts DC). It works well measuring the power line voltage.

I wish I had a scope, but I suspect it's AC induced from the power lines (high intensity power lines run on the same poles as the phone line around this block). There's also a lot of outside plant work going on installing FiOS.

Reply to
MCO

"MCO" wrote in news:h8qdnXZybKuIbVHZnZ2dnUVZ snipped-for-privacy@comcast.com:

The typical 20hz ring voltage that should be found at the NI should be at

55 Volts RMS AC superimposed on DC line current capable of ringing up to four C4 type bridged ringers. Telcordia GR-506 (1996) allows for a minimum ring voltage objective of 40VAC Rms. See the excerp from an GR 506 (1996), below.

Another good reference regarding loop signaling ringing requirments is ANSI T1.401.

Bill.

14.1 Alerting Signals Using Ringing

A ringing signal consists of a repeated grouping of one to three bursts of ringing. Theringing bursts can be short or long. The ringing bursts are separated by a relative short silentintervals (intra-group) while the groups of ringing bursts are separated by a longer silentinterval (inter- group).

The combination of the ringing bursts and the silent intervals makeup a ringing pattern. A ringing pattern is repeatedly applied to an access line until thecalled-party answers the call, until the calling-party abandons the call attempt, or a networktimeout occurs. The requirements for the duration of the short ringing bursts, the longringing bursts, the intra- group short silent intervals, and the inter-group long silent intervalsfor ringing patterns are given in this section.

Alerting signals using ringing are only usedby SPCS access line interfaces that use loop-start or ground-start signaling.The criteria for the ringing capacity of an SPCS, the number of access lines that must berung simultaneously, is contained in TR-TSY-000511, LSSGR: Service Standards, Section11.

14.1.1 Ringing Source Criteria

The following criteria apply to the source of the 20-Hz ac component of ringing signals.

R14-1[539] The applied ringing voltage shall meet the duration-limited sourcesafety requirements of GR-1089-CORE.

R14-2[540] The frequency of the ringing voltage shall be 20 1 Hz.R14-3[541] The open-circuit magnitude of the ac component of ringing voltageshall be

84 V rms and 104 V rms.The 104 V rms maximum assumes that the magnitude of the dc component of the ringingvoltage is 52.5Vdc and that the crest factor of the ac component is 1.4142.

If a highermagnitude dc component is used or the crest factor of the ac component is higher, the peakvoltage of the ac component of the ringing signal must be reduced to meet the duration-limited source safety requirements of GR-1089-CORE.

R14-4[542] The crest factor of the ac component of the ringing voltage shall be1.35 and1.45.The crest factor of an ac signal is defined as its peak-to-rms voltage ratio.

R14-5[543]During application of ringing, the ac ringing current shall not exceed220 mA at any phase angle into any ringing load.

R14-6[544] An SPCS shall provide a minimum ringing voltage of 40V rmsacross a ringing load of 5 REN at the end of any access line with a loopresistance (Rdc 400) ohms.Part 68 of the FCC Rules and Regulations require that all registered customer installationequipment that can affect on-hook impedance have a Ringer Equivalence Number (REN).A ringing load of 1 REN for equipment designed for 20 Hz ringing has an impedance of7000 ohms at 20 Hz. Thus, a load of 5 REN has an impedance of 1400 ohms at 20 Hz. A1386 ohm resistor in series with a 40F capacitor should be used as a 5 REN load for theabove criteria.

R14-7[545] During application of ringing and during ring-trip, the bridgedC-weighted noise referenced to 900 ohms shall be 90 dBrnC and theanalog voiceband lead conducted emissions criteria of GR-1089-CORE shall be met.

14.1.2

Initial Application of Ringing Customer Customer confusion can result when a called party attempts to originate a call after anSPCS completes connection to the access line but before the SPCS applies a ringing burstto the line. The criteria in this section help minimize the probability that this confusion occurs

The requirements on call completion delay up to the time that an SPCS attaches a calledaccess line to aringing circuit are contained in TR-TSY-

000511. These call completiondelay requirements assume that the architecture of the SPCS is such that aringing circuitcan be identified.

CR14-8[546] If the architecture of the SPCS is such that aringing circuit can beidentified, a ringing burst shall be applied to an access line within

500 msafter the ringing circuit is connected to the access line.

CR14-9[547] If the architecture of the SPCS is such that aringing circuit can notbe identified, the call-completion delay requirements of TR-TSY-

000511(post-dialing delay) apply until the application of a ringing burst to thecalled access line.

R14-10[548] Upon the initial application of ringing pattern 1 of requirement[554],the first burst of ringing applied to an access line may be shorter that theminimum duration required by requirement[554]. However, the durationof the first ringing burst applied to an access line shall be

400 ms.O14-11[549]It is an objective that the duration of the initial application of ringingpattern 1 of requirement[554] meet the minimum duration required by[554].

R14-12[550] Upon the initial application of ringing patterns 2 through 5 ofrequirement[554], the ringing burst shall be applied in the order listedbeginning with the first ringing burst. The first ringing burst shall meet theminimum requirements of[554]. If an SPCS meets the ringing durationobjective of[555], the first ringing burst shall meet the minimumrequirements of[555].

14.1.3 Ringing Applied to Individual-Service Access Lines

This section specifies ringing patterns applied to individual-service loop- start lines andground-start access lines, and coin telephone lines.

A individual-service access line servesonly one customer. The use of the following ringing patterns for services is covered byother documents in the LSSGR, such as TR-TSY-000520,LSSGR: Features Common toResidence and Business Customers I. Ringing patterns applied to multi-party access linesare covered in Section6.4.7 and TR-TSY-000561.

The ringing pattern requirements in this section accommodate existing SPCS designs. It ishighly desirable that new SPCS designs meet the objectives in this section.

14.1.4Ring Trip

The following criteria apply when a loop closure is applied during the alerting state to aloop-start or ground-start SPCS interface.

R14-21[559] The alerting signal shall be removed within 200 milliseconds after aloop closure is applied during the alerting state. This requirement shall be met if the loop closure is applied during a ringing burst or during a silentinterval.

O14-22[560] It is an objective that the alerting signal be removed within

100milliseconds.

R14-23[561] The alerting signal shall not be removed when applied to a zero-ohmloop with the following components connected in parallel from the ringconductor to the tip conductor of the interface.2 microfarad capacitor;

5 C4A ringers;10,000 ohm resistor.

R14-24[562] The alerting signal shall not be removed when a 200-ohm loopclosure is applied to the interface for 12 milliseconds through a zero- ohmloop.

Reply to
Bill

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