[Asterisk-Users] Re: Grandstream Quality Survey.... :P

[Robert Hajime Lanning]

<quote who="rnc Info Lists">
>> Is that FCC sticker on the back of the phone for real?
>>
>> A customer could not use his computer while talking on his GS BT102 phone.
>> The customer was using a major name wireless keyboard/mouse with his pc.
>> The keyboard/mouse stops working if the GS phone is too close.
>>
>> --
>> Bob Knight
>> [-w] the work option
>> bk at minusw.com
>> 925-449-9163
>>
>>
> Both the wireless keyboard and the GS are probably Part 15 devices which
> must accept interferance that other services cause to them (ie.. there is
> no protection from other "licensed" services' interferance) and are
> limited in range  as to the emissions that they can generate.  If those 2
> devices are sitting next to each other then they both can probably be FCC
> rules compliant and still cause each other problems.
>
> I might have the FCC rule part wrong but think that the concept is right.

I am a HAM and here is some excerpts of what the ARRL's interpretation is,
of Part 15:
                        "Myths:"

 There are a lot of urban myths about Part 15 rules and devices. The first is
that their signal levels are very small and it is not likely that they will
cause harmful interference. Although this is true in most cases, the radiated
emissions levels in Part 15 were designed to protect one neighbor's
television reception from another neighbor's video game, as an example. The
permitted radiation levels are not enough to always protect sensitive amateur
reception. As one example, intentional radiators and carrier-current devices
are permitted a field strength of 30 microvolts/meter at 30 meters distance
from the source. On HF, this legal signal, if heard on an 80 meter half-wave
dipole, would result in a received signal of S9+15 dB on most receiver S
meters! This clearly would be harmful interference in the Amateur Radio
Service.

Many hams believe that all devices regulated by Part 15, including
transmitters and digital devices, are "type accepted" by the FCC, with testing
in the FCC Lab. Type acceptance has actually been written out of the FCC
rules. Devices that were Type Accepted under the old rules are now subject to
Certification or a Declaration of Conformity. To obtain Certification, a
manufacturer supplies test data to the FCC, usually from a laboratory that the
FCC knows and trusts, and Certification is usually issued on the basis of the
test data and other information about the product. In a Declaration of
Conformity, the manufacturer issues a formal statement to the FCC that the
device has been tested at an accredited laboratory and that it complies with
the rules.

Although the FCC can call in equipment for testing, in almost all cases, the
FCC does not actually perform testing on equipment covered by Part 15. They
usually review information and test data supplied by the manufacturer. Most
computing devices are subject to Certification or a Declaration of Conformity.

And another interesting piece, who is responsible:

 The FCC rules require the equipment manufacturer or importer to design and
test his products to ensure that they do not exceed the absolute maximum
limits. In addition, the FCC requires that Part 15 devices be operated in
such a way that they not cause harmful interference. The operator of the Part
15 device is responsible for correcting the interference or to stop using the
device if so ordered by the FCC. This can create a very difficult situation.
Imagine that the neighbor of a ham goes to a local retail store and buys a
Part 15 device. If the device causes harmful interference, the rules place
the responsibility of proper operation and correction of the interference on
the user. This can put a ham into the unenviable position of having to
explain to a neighbor that the device he or she just bought at a local store
is being used in violation of federal law! The resultant disagreement is not
unexpected.

Then the main part, that all licenced devices must adhere to:

§ 15.5 General conditions of operation.

(a) Persons operating intentional or unintentional radiators shall not be
deemed to have any vested or recognizable right to continued use of any given
frequency by virtue of prior registration or certification of equipment, or,
for power line carrier systems, on the basis of prior notification of use
pursuant to § 90.63(g) of this chapter.

(b) Operation of an intentional, unintentional, or incidental radiator is
subject to the conditions that no harmful interference is caused and that
interference must be accepted that may be caused by the operation of an
authorized radio station, by another intentional or unintentional radiator, by
industrial, scientific and medical (ISM) equipment, or by an incidental
radiator.

(c) The operator of a radio frequency device shall be required to cease
operating the device upon notification by a Commission representative that the
device is causing harmful interference. Operation shall not resume until the
condition causing the harmful interference has been corrected.

(d) Intentional radiators that produce Class B emissions (damped wave) are
prohibited.

The label should say:
This device complies with part 15 of the FCC Rules. Operation is subject to
the following two conditions: (1) This device may not cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.

And the manual should say:
This equipment has been tested and found to comply with the limits for a Class
A digital device, pursuant to part 15 of the FCC Rules. These limits are
designed to provide reasonable protection against harmful interference when
the equipment is operated in a commercial environment. This equipment
generates, uses, and can radiate radio frequency energy and, if not installed
and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a
residential area is likely to cause harmful interference in which case the
user will be required to correct the interference at his own expense.

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       -MCP