16 Dec
2010
16 Dec
'10
10:09 a.m.
Hi all,
i just wanted to keep you posted with the 2011 roadmap for 3G integration
into our "Free Software Mobile Network" stack. This message summarizes
the plan of what I expect to be working on. Comments welcome.
3G support directly in OpenBSC is, however, a bit more difficult than we
originally anticipated. The primary problems are:
* 3G and 2G share the same core network (CN = MSC/VLR/HLR/AuC/SGSN/GGSN)
but have different radio access netowrk (RAN = BTS+BSC vs. NodeB+RNC)
* the interface between RAN and CN is different, i.e. 'A' interface
(08.08) in GSM case, RANAP in 3G case.
* The encoding of the two protocols could not be any different. Hand-coded
vs. complex ASN.1 structures
So with OpenBSC, we face the following challenges:
1) We implement the GSM-RAN functionality and the CN in one process,
without any separation or standardized interfaces between them
2) Implementing RANAP in C can be done, but is probably quite cumbersome
given the tons of code asn1c generates and how difficult it seems to
get all the memory allocation/freeing right in all the cases
What we instead decided to do is:
a) Split the BSC part from the CN by implementing the A interface (this
is already finished, we now have osmo-bsc to do exactly that)
b) Implement a new MSC part, using the A interface towards the BSC
This is still possible using our existing code in the original
OpenBSC, though we have not completed/finished it yet.
The real goal is to have a new MSC, written in a higher-order language
that provides proper tools for working with ASN.1 - e.g. Erlang. I have
just started working on this and am more or less finished with the lower
layers like SCCP and am moving into 08.08 and the actual layer3 protocols.
There is already some initial funding secured for the first months of
this work, and funding will likely continue.
c) Once the 2G functionality of the Erlang MSC is working, add the RANAP
interface to it.
At this point we should more or less be able to directly
connect the Alcatel-Lucent femtocells, as they basically consist of
HomeNodeB plus an internal RNC handling the RRC protocol.
d) Adding support for ip.access/Cisco/AT&T will need an implementation of
their URSL protocol, which is proprietary. URSL can either be added
to the new MSC directly, or a URSL<->RANAP translater be developed.
e) Adding support for the Ubiquisys/SFR femtocell would require us to implement
the UMA protocol stack. This can once again be either done as part of
the MSC or using an external translator/gateway program.
Regards,
Harald
--
- Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/
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16 Dec
16 Dec
10:57 a.m.
Hi Harald and list,
Which model of available femtocells are you focusing on and is it easy
to purchase one (on ebay perhaps)? Cause for 2G the ip.access's nanoBTS
imho is best supported by openbsc. If you can give us some more
information what device to use (as a start), than we can at least focus
on one device and extend to other models in the future.
On 16-12-2010 10:09, Harald Welte wrote:
Hi all,
i just wanted to keep you posted with the 2011 roadmap for 3G integration
into our "Free Software Mobile Network" stack. This message summarizes
the plan of what I expect to be working on. Comments welcome.
3G support directly in OpenBSC is, however, a bit more difficult than we
originally anticipated. The primary problems are:
* 3G and 2G share the same core network (CN = MSC/VLR/HLR/AuC/SGSN/GGSN)
but have different radio access netowrk (RAN = BTS+BSC vs. NodeB+RNC)
* the interface between RAN and CN is different, i.e. 'A' interface
(08.08) in GSM case, RANAP in 3G case.
* The encoding of the two protocols could not be any different. Hand-coded
vs. complex ASN.1 structures
So with OpenBSC, we face the following challenges:
1) We implement the GSM-RAN functionality and the CN in one process,
without any separation or standardized interfaces between them
2) Implementing RANAP in C can be done, but is probably quite cumbersome
given the tons of code asn1c generates and how difficult it seems to
get all the memory allocation/freeing right in all the cases
What we instead decided to do is:
a) Split the BSC part from the CN by implementing the A interface (this
is already finished, we now have osmo-bsc to do exactly that)
b) Implement a new MSC part, using the A interface towards the BSC
This is still possible using our existing code in the original
OpenBSC, though we have not completed/finished it yet.
The real goal is to have a new MSC, written in a higher-order language
that provides proper tools for working with ASN.1 - e.g. Erlang. I have
just started working on this and am more or less finished with the lower
layers like SCCP and am moving into 08.08 and the actual layer3 protocols.
There is already some initial funding secured for the first months of
this work, and funding will likely continue.
c) Once the 2G functionality of the Erlang MSC is working, add the RANAP
interface to it.
At this point we should more or less be able to directly
connect the Alcatel-Lucent femtocells, as they basically consist of
HomeNodeB plus an internal RNC handling the RRC protocol.
d) Adding support for ip.access/Cisco/AT&T will need an implementation of
their URSL protocol, which is proprietary. URSL can either be added
to the new MSC directly, or a URSL<->RANAP translater be developed.
e) Adding support for the Ubiquisys/SFR femtocell would require us to implement
the UMA protocol stack. This can once again be either done as part of
the MSC or using an external translator/gateway program.
Regards,
Harald
11:06 a.m.
Which model of available femtocells are you focusing
on and is it easy to
purchase one (on ebay perhaps)? Cause for 2G the ip.access's nanoBTS imho is
best supported by openbsc. If you can give us some more information what
device to use (as a start), than we can at least focus on one device and
extend to other models in the future.
Did you read the mail ?
It explicitely mention :
in point (c) -> "the Alcatel-Lucent femtocells"
in point (d) -> "ip.access/Cisco/AT&T" femtocells
in point (e) -> "Ubiquisys/SFR femtocell"
Google for those ..
Cheers,
Sylvain
11:19 a.m.
Sure I read the mail, but these are three models, I don't have the
money to afford three femtocells. I'm glad to have just one to play
with. Or you can give me some of yours...
On 16-12-2010 11:06, Sylvain Munaut wrote:
Which model of
available femtocells are you focusing on and is it easy to
purchase one (on ebay perhaps)? Cause for 2G the ip.access's nanoBTS imho is
best supported by openbsc. If you can give us some more information what
device to use (as a start), than we can at least focus on one device and
extend to other models in the future.
Did you read the mail ?
It explicitely mention :
in point (c) -> "the Alcatel-Lucent femtocells"
in point (d) -> "ip.access/Cisco/AT&T" femtocells
in point (e) -> "Ubiquisys/SFR femtocell"
Google for those ..
Cheers,
Sylvain
11:24 a.m.
Sure I read the mail, but these are three models, I
don't have the money to
afford three femtocells. I'm glad to have just one to play with.
Maybe you can read the _rest_ of those paragraphs :
c) "... add the RANAP interface to it. At this point we should more or
less be able to directly ..."
d) "Adding support for ip.access/Cisco/AT&T will need an implementation of
their URSL protocol"
e) "Adding support for the Ubiquisys/SFR femtocell would require us to implement
the UMA protocol stack."
Seems pretty clear that the ones mentionned in point c) will work
first since it can use RANAP _directly_ while the two others will need
RANAP <-> URSL or RANAP <-> UMA translators.
Or you can
give me some of yours...
Sure, our time working on the project and answering your question
isn't enough for you ? you want our money and equipment as well now
???
Sylvain
11:19 a.m.
in point (c) -> "the Alcatel-Lucent
femtocells"
in point (d) -> "ip.access/Cisco/AT&T" femtocells
in point (e) -> "Ubiquisys/SFR femtocell"
About Femtocells.... i already started to work on Vodafone Sure Signal and i would like to
work also on Femtocells of others countries.
Are six months that i'm searching on ebay femtocells... but i can find only
Vodafone's.
Have you other online shops to suggest?! Especially for SFR and Ubiquisys?!
Thank you list
11:33 a.m.
Hi,
Are six months that i'm searching on ebay
femtocells... but i can find only Vodafone's.
Just did a quick search and I could find one of each model:
http://cgi.ebay.co.uk/Vodafone-Sure-Signal-/200554104589?pt=UK_Mobiles_Acce…
http://cgi.ebay.com/AT-T-3G-Microcell-ATT-Femtocell-mini-cellular-tower-/23…
http://annonces.ebay.fr/viewad/SFR-Home-3G-une-couverture-3G-optimale-a-dom…
Vodafones are prevalent that's true, but the others are no way as hard
to find as nanoBTS's.
Have you other online shops to suggest?! Especially
for SFR and Ubiquisys?!
Very often it's only the operators (or reseller for the operator) that
sell the femtocell (since they're 'customized' for a particular
network/operator).
Vodafone seems a little more "lax" in selling them (not checking if
you have a subscription or not) so that's why they're easility found
on ebay. AT&T are also found on the US ebay or craigslist without much
difficulty.
The SFR ones can be bought from SFR if you have a subscription.
They're a little less found on auction sites (I guess less people
re-sell them ?) but it's possible (
http://annonces.ebay.fr/viewad/SFR-Home-3G-une-couverture-3G-optimale-a-dom…
)
But each time you have to search for whatever name the operator has
for it (like "Home 3G" for SFR, or "Sure Signal" for Vodafone, ...)
Cheers,
Sylvain
11:29 a.m.
Sorry, appearantly I wasn't awake as I thought.
On 16-12-2010 11:06, Sylvain Munaut wrote:
Which model of
available femtocells are you focusing on and is it easy to
purchase one (on ebay perhaps)? Cause for 2G the ip.access's nanoBTS imho is
best supported by openbsc. If you can give us some more information what
device to use (as a start), than we can at least focus on one device and
extend to other models in the future.
Did you read the mail ?
It explicitely mention :
in point (c) -> "the Alcatel-Lucent femtocells"
in point (d) -> "ip.access/Cisco/AT&T" femtocells
in point (e) -> "Ubiquisys/SFR femtocell"
Google for those ..
Cheers,
Sylvain
4888
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7 comments
4 participants
participants (4)
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Harald Welte -
luca bongiorni -
Nordin -
Sylvain Munaut