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Nordin bouchtaoui at gmail.comOn 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 at 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 :-) >> >> >> >> >