Subject: [MOBILE-IP] 3G Mobile Architectures

From: "BINAR, Simon" <[email-masked]>
Date: Wed, 5 Jan 2000 11:44:10 -0000

Hi everyone.

There have been recently a lot of discussions on this mailing list about
how to make MIP suitable for 3G networks. As most people on this list
will know, one of the driving forces behind the standardisation of 3G is
3GPP (I'm a European, so I want talk here about 3GPP 2). Looking at the
discussions in 3GPP and the MIP WG of the IETF, it seems to me that both
groups are taking different approaches to solve the same problem, and I
would like to get some opinions from list members why the IETF model
could be better/worse than the 3GPP model.

Essentially, the difference I see in the discussions is that the MIP WG
assumes in many cases base stations to be IP addressable devices. In
other words, the "IP cloud" reaches all the way to the utmost edge of
the wireless network. In 3GPP however, the access network is considered
(as far as I understand) to be a separate entity. Currently, it seems
that the UTRAN is based on ATM transport, IP could be used as an option
(correct me if I'm wrong). The higher-layer signalling protocols used in
the access network for R'99 are very much SS7 oriented (using things
like RANAP, the Radio Access Network Application Part). In this
architecture, it seems to me that IP is not "all-embracing", and is
restricted more to the core network...

Here is now my question: which advantage is there to have IP totally
completely utterly all-embracing in the wireless network as opposed to
have it deployed only in the core network? My first guess is that there
might be advantages in the area of network management (but I'm not an NM
expert, therefore, I'd like to get comments from more knowledgeable
people in this area). I think that arguments such as "the IETF approach
is more elegant" is not valid, since, by the end of the day, we also
have to think about business...

Anyway, this was my question, and as usual, comments are most welcome...

Simon Binar

---

From: Rami Gabriel Mukhtar <[email-masked]>
Date: Fri, 7 Jan 2000 11:19:36 +1100

> have to think about business...

Simon, these are my thoughts...

Bringing IP addresses out to the base station has the advantage
of making the network far more flexible.

Although currently cellular networks are large proprietary networks,
they may not be in the future.

In the future as base station density increases and access to IP
networks becomes more predominant, it may be cheaper for a Telco
to connect additional base stations to an existing IP network
with a SLA rather than run another leased line to the base station.
In order for this to be practical,  base stations need to be
IP addressable.

From another perspective, operators may wish to connect small
clusters of base stations directly
to the internet.  For example a company may wish to connect a single
private cell to the internet to enable network access within a building
without incurring expensive Telco charges.  If the base station is IP
addressable this can be done without having to construct a core
network.

Hope this helps,

Regards,
--
Rami Mukhtar
___________________________________________
Post Graduate Student
Telecommunications Group
The University of Melbourne
Ph: (03) 9344-9207
WWW:  http://www.ee.mu.oz.au/pgrad/rgmukht
___________________________________________