was also looking on the Iub specs today and my head hurts :(.
For femtos the default interface would be Iuh, which from what I
understand is the Home Node B adapted version of the NodeB Iub. Then
you'd need a sort of Access Controller in the form of an Home Node B
Gateway as the next hop, but otherwise it seems to be less of packaging
hassle, or?
- data
transport in 10 pages, CS with RTP multiplexed in UDP/IP, PS with
GTP-U/UDP/IP
- Home
Node B Application Part - SCTP/IP
I was wondering if you looked at this too...
I know that Iub would be the real deal and fortunately this femto has it
too. Also probably the advantages are offset but what you loose by
requiring one more box, the Home Node B Gw.
Cheers,
-Dragos
Nordin wrote:
On 9-6-2010 20:35, Milos Prodanovic wrote:
I have some experience with ASN.1
coding/decoding, but not with PER,
and I
have no experience with any 3gpp or mobile documents or standards.
I'm interested to look at ASN.1 PER encoding in spare time, if
someone can
point me to documents that explain where ASN.1 is used (the purpose),
and to
point me to documents that holds ASN.1 syntax needed for this purpose.
I'm currently studying the UMTS specs to get a general understanding
and focus on the Iub interface part to find the basic messages that
are similar to the OML/RSL part of GSM. As far as I understand there
are parts, if not all, of the messages encoded in ASN.1 PER, even
unaligned as Harald already told us before. I don't know much of the
details, maybe Harald can put more light on this.
You might want to experiment with PER encoded messages to play with
and on the wiki you can find pdfs about ASN.1 and PER.
http://en.wikipedia.org/wiki/Packed_Encoding_Rules
But at the moment I found these interesting docs about Iub interface,
that's like the GSM's Abis interface for UMTS:
http://www.3gpp.org/ftp/Specs/archive/25_series/25.430/25430-650.zip
http://www.3gpp.org/ftp/Specs/archive/25_series/25.433/25433-6h0.zip
(this is a huge file, almost 1000 pages!)
http://www.3gpp.org/ftp/Specs/archive/25_series/25.435/25435-650.zip
http://www.3gpp.org/ftp/Specs/archive/25_series/25.427/25427-680.zip
As far as I understand we can divide Iub into two networklayers, one
is the Radio Network Layer and the other is Transport Network Layer.
According to the specs the Tansport Network Layer is based on ATM/AALx
/etc.. or SCTP/IP combination, but I assume ip.access's 3G femtocell
(the one I want to focus on) is just based on tcp/ip, just like the
nanobts.
The Radio Network Layer can be split in two parts, the Control Plane
and the User Plane. The Control Plane is based on NBAP which is doing
signaling for Node B, just like OML for the BTS. So I think that's an
important part to start with as this part is to control the Node B to
get it on the air.
The other part is the User Plane and is based on Common channels and
Dedicated channels, comaparable with the RSL layer.
Also for those who didn't know yet, UMTS doesn't work with
channels/timeslots like GSM, it works with so called cells. I don't
know the details yet, but what I remember is that you have to
configure each cell for a certain purpose, like DCH, PCH etc...
That's what I found about the UMTS so far, if I misunderstood some
things about the UMTS, don't hesitate to correct me. If someone can
add more information about it in plain English, that would be great,
cause all the new acronyms makes me a bit dizzy.
Peace...
On Mon, Jun 7, 2010 at 3:51 PM,
Nordin<bouchtaoui(a)gmail.com> wrote:
Well guys,
Just being curious, are there any plans for UMTS support?
I remember Harald said something about an ASN.1 PER was an obstacle to
start for UMTS support.
Are there also nanoBTS for UMTS, I only know of 2G devices...
It was just quite on the list :p
Greetz,
Nordin :-)