Geoff, et. al.
Let me try to be a bit clearer why I am
suggesting we stick with air-interface and why I do not think the term
radio-link is appropriate in this context.
First, I wholly endorse using terms that
are well understood by the industry and defined by others - if we use
them to refer to the same thing. That is actually why I believe that using
radio-link and radio-link protocol for what 802.20 is doing is inappropriate. The
term radio-link and radio-link protocol (RLP) in 3G have very specific meanings.
In particular the RLP is actually a protocol above the MAC layer (see 3GPP2 C.S0024
and e.g. 3G document 24.022) - it certainly does not include the PHY and MAC layers.
So if we were to refer to what we are specifying as part of the RLP we would actually
be creating confusion with the 3G community rather then helping them
understand.
On the other hand, the term air-interface
is in common usage by organizations working on both fixed wireless and mobile
specifications.
- 802.16's title refers to "Air Interface" and the first
sentence in the base 802.16 standard reads " This standard specifies
the air interface, including the medium access control layer (MAC) and
physical layer (PHY), of fixed point-to-multipoint broadband wireless
access (BWA) systems providing multiple services."
- 3GPP2 has specifications with titles such as "cdma2000 High Rate Packet Data Air Interface Specification"
[3GPP2 specification 3GPP2 C.S0024]. Below is a diagram from that
specification showing where the air-interface is:
[Figure from page 1-2 ]
That is clearly consistent with definition
2.
So on balance I believe the correct choice
is to stick with the term air-interface; this will
facilitate communications with other groups. The base standard, just
like 802.16's base standard, can then add the appropriate qualifiers as
to which layers and/or aspects of the air-interface are being addressed.
Regards
Mark Klerer
-----Original
Message-----
From: Geoff Anderson
[mailto:meerkats@hvc.rr.com]
Sent: Wednesday, October 08, 2003
7:16 PM
To: 'Klerer Mark'; 'Jim Mollenauer'
Cc: 'Gang Wu';
stds-80220-requirements@ieee.org
Subject: RE:
stds-80220-requirements: Definition of "air interface"
Mark,
Thanks for the comments. I think your discussion
actually made the case for getting rid of the term air-interface because it
really does lack any descriptive information about what we are developing.
Therefore, I would use the language of your definitions with
the following changes:
Definition:
1) The radio-link is the radio-frequency
portion of the transmission path between the wireless terminal (usually
portable or mobile) and the active base station or access point.
2) The radio-link is the shared boundary
between a wireless terminal and the base station or access point.
The introduction to the final standard would read:
This standard specifies the layer 1 and
layer 2 Radio Link Protocol or RLP, between compliant wireless terminals and
base stations.
I don't think there is anything that would preclude us
from using terminology that is already used in other standards. In fact,
this may help many of our 3GPP/2 members understand what it is we are trying to
standardize, since they have already done it.
Best Regards,
geoff
Geoffrey T.
Anderson
Polar Industries,
Inc.
45 Roe Avenue
Cornwall on Hudson,
NY 12520-1403
Phone: 845-534-4589
Fax: 845-818-3513
Cell: 914-843-9572
-----Original
Message-----
From:
owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org] On Behalf Of Klerer Mark
Sent: Wednesday, October 08, 2003
4:23 PM
To: 'Jim Mollenauer'; Geoff
Anderson
Cc: 'Gang Wu';
stds-80220-requirements@ieee.org
Subject: RE:
stds-80220-requirements: Definition of "air interface"
I
agree with Jim Mollenauer. Specifically the term RLP as used by Jim Tomcik
actually refers to a very specific protocol used in UMTS. Here is the
definition of RLP:
RLP - Radio Link Protocol
Radio Link Protocol terminates at the MS (Mobile Station)
and the IWF (Interworking Function) generally located at the MSC (Mobile
Switching Centre). It utilizes the reliability mechanisms of the underlying
protocols in order to deliver data. (http://www.mpirical.com/companion/mpirical_companion.html#http://www.mpirical.com/companion/GSM/RLP_-_Radio_Link_Protocol.htm)
I
would like to toss out the following for people to consider.
Considerata:
The word "Interface" is somewhat ambiguous in that we are using it in
the two senses given in Webster's:
2 a
: the place at which independent
and often unrelated systems meet and act on or communicate with each other
<the man-machine interface>
b : the means by which interaction
or communication is achieved at an interface
we seem to be using it in
both the sense of 2a and 2b. This is the root of the difference in the two
definitions that have been shared. So we could speak about an
air-interface and even an air-interface interface.
We have the definition
provided by Gang Wu (via the Intel website) : the air interface is the radio-frequency portion of the circuit between
the cellular phone set or wireless modem (usually portable or mobile) and the
active base station.
And
the one provided by Dan Gal (via the Ericsson web-site): "The air interface is the shared boundary between a
mobile and the base station."
IEEE
100 (The Authoritative Dictionary of IEEE Standards Terms) provides the
following "general definition" [def 4] for "interface": A shared boundary
Suggestion for a way forward:
I would
therefore suggest the following: We define air-interface as:
Definition:
1)
The air interface is the radio-frequency
portion of the transmission path between the wireless terminal (usually
portable or mobile) and the active base station or access point.
2) The air interface is the shared boundary
between a wireless terminal and the base station or access point.
I
am trying to avoid using air-interface interface, and I believe that 2 in
essence is taking a look at the "cross section" of the air interface between
the mobile and base station. I have paraphrased definition one to remove the
term "circuit" and replace it with the more generic
"transmission path" due to the potential connectionless packet nature
of the path.
The
intro/preamble to the actual standard could then read eg:
This
standard specifies the layer 1 and layer 2 protocols of the air-interface
between compliant wireless terminals and base stations. (English to be fixed
and polished when we get there).
In
the requirements document we can put a similar statement in the overview. Note
that the discussion as to whether we indicate what layer a requirement applies
to is a separate issue.
This
is in line with IEEE standards, 3G standards and ISO standards that all use the
term air interface in a similar manner.
Sorry
about this somewhat lengthy epistle. I hope it helps in getting us towards
closure.
Mark
-----Original
Message-----
From: Jim Mollenauer
[mailto:jmollenauer@technicalstrategy.com]
Sent: Wednesday, October 08, 2003
3:04 PM
To: Geoff Anderson
Cc: 'Gang Wu';
stds-80220-requirements@ieee.org
Subject: Re:
stds-80220-requirements: Definition of "air interface"
I respectfully disagree. A protocol and an
interface are not the same thing. A protocol specifies what happens when,
and generally involves several information transfers across one or more
interfaces. An interface is the boundary between two entities, across
which information may flow according to some protocol.
The term "air interface" emphasizes that we are standardizing the
information flow through the air between two systems, and not across some
internal wired interface within one of the systems. Calling it a
"radio link" is confusing: does that imply link layer or physical
layer?
Let's keep "air interface".
Jim Mollenauer
Geoff Anderson wrote:
I think
Jim Tomcik had discussed a term Radio Link Protocol, or RLP during the San
Francisco meeting. After replacing Air Link with Radio Link or Radio Link
Protocol in the document and then re-reading, it seems to make much more sense.
I would
agree with Alan's 10/2 proposal to remove Air Interface and replace with Radio
Link or Radio Link Protocol where it makes sense. Also this decision
would carry forward to all documents of 802.20, as Alan proposed.
geoff
Geoffrey
T. Anderson
45 Roe
Avenue
Cornwall
on Hudson, NY 12520-1403
Phone: 845-534-4589
Fax: 845-818-3513
Cell: 914-843-9572
-----Original
Message-----
From: owner-stds-80220-requirements@majordomo.ieee.org
[mailto:owner-stds-80220-requirements@majordomo.ieee.org]
On Behalf Of Gang Wu
Sent: Thursday, October 02, 2003
2:33 PM
To: stds-80220-requirements@ieee.org
Subject: stds-80220-requirements:
Definition of "air interface"
At
least I found one from the web.
"In
cellular telephone communications, the air interface is the radio-frequency
portion of the circuit between the cellular phone set or wireless modem
(usually portable or mobile) and the active base station."
Regards,
Gang
Wu