On Saturday, October 13, 2001, at 03:13 , Ben Hutchings wrote:
>> 1) if they did that, then they would instantly loose their roaming
>> income from traditional roaming with that network as all their roamers
>> could not roam anymore in that network. Reason being that they can only
>> switch off all or nothing.
>
> Yes, I understood that, but the uncooperative network might have roaming
> agreements with competitors of the ZEBRA implementor in the same area,
> so they wouldn't lose much. (My network has roaming agreements with all
> 4 operators in Germany, for example.)
Yes, but cancelling the roaming agreement means also that they don't get
any visitors from that network anymore because those agreements are
bilateral.
Having said that, these days many operators have outsourced roaming
agreements to clearing houses. They sign up with the clearing house and
get a package of -say- 200 roaming partners. If they do not wish to let
any of their users roam with a particular network they will have to
shell out extra money for custom services which can be as expensive as
it was to maintain all those roaming agreements inhouse.
It is very unlikely for any network to cancel any roaming agreements
based on a complementary service being offered that only serves
customers who have either no or a restricted roaming facility, i.e.
customers that would otherwise be refused service or those who have
actively opted-in.
In reality it is consortia who make the decision to deploy technologies
like ZEBRA, not individual networks. Likewise with roaming agreements.
It is unlikely they would want to start a trade war by retaliating for
competitive advantage in one market with denial of service in another. I
suppose that would also not go down well with public opinion not even to
mention the regulators or competition watchdogs.
ZEBRA has the ability to divert roamers to a particular network. It's
more of a side effect than intentional. However, operators didn't want
to even think about the possibility exactly because they do not want to
start a trade war. They want to leave it up to their customers to decide
which network they want to roam with.
More interestingly, one UK network which has no ties with Spain, was
interested to arrange for some network in Spain to offer the service to
their customers when travelling to Spain even though they know they
don't get a share in the revenue. Their idea was that the ability to
roam in the UK's most important holiday destination on a new consumer
service was so interesting that users of their competitors might switch
and choose their network instead.
I believe it is a common misperception that operators are in for
retaliatory action. It is more likely they will instead follow the
example of a successful deployment and soon deploy too in order to grab
the tourists visiting their country.
So far I have not heard about any operator who rejected the idea of "VN
charges" based roaming. Everybody I have been talking to rather liked
the idea. It's one of those things where people say "Oh, I see, that's
neat - why didn't anybody think about this before - It's so simple" etc.
>> 2) ZEBRA includes an alternative authentication system called Secure
>> Visitor Authentication (SVA) which is based on public key encryption
>> and
>> allows the visited network to authenticate the handset directly for the
>> duration of the visit.
>
> Surely this still requires the home network to provide a public key to
> the
> visited network on deman, and to identify the algorithms used?
No, it is based on the SIM toolkit. VN and handset exchange public keys
upon first sign-on. However, this is only an option and it requires an
extra AuC in the VN. However, this also benefits the traditional roaming
service in cases where networks want to cut down on bandwidth where
today they reuse the triplets (not recommended but practised by some
networks).
rgds
BK
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Received on Fri Oct 12 22:06:00 2001