Implementing a Native IMS Location Service Enabler over a Prototypical IMS Core Network Testbed

Peter Reichl1, Sandford Bessler1, Joachim Fabini2, Rudolf Pailer3, Joachim Zeiss1

It proposes a location architecture that has nothing to do with TS 23.271. It is based on GPS-enabled terminals and integrates with presence information. They have actually implemented a testbed.

IMS Interoperability and Conformance Aspects

Mischa Schmidt, Andreas Wilde and Anett Schülke Henrique Costa

Describes the importance of the interoperability tests organized by various organizations.

Interworking of Wimax and 3GPP Networks based on IMS

Fangmin Xu, Luyong Zhang, and Zheng Zhou

The authors reproduce part of the work of 3GPP in WLAN- IMS internetworking, introduce the QoS capabilities of IMS, and finally describe QoS guarantees, AAA provision, and security. It seems to me that it is not a closed and clear solution, but at least is some talk about our topic of interest.

Location-based services -- an overview of the standards

P M Adams, G W B Ashwell and R Baxter

This documents describe the trajectory and organization of different standard bodies that influence in the location services. Quite useful.

3GPP TS 23.207 V6.6.0 (2005-09)

3rd Generation Partnership Project;
Technical Specification Group Services and System Aspects;
End-to-end Quality of Service (QoS) concept and architecture
(Release 6)

This time we are talking about GPRS and end-to-end. Much more complete than the previous. I clarifies that the AF can be the CSCF. The Gq and Go Interface are also described. It also esplains that both DS (differentiated services) and RSVP can be used to guarantee QoS in the IP core network and remote link. It assumes that since GPRS is used in the local link, the PDP flow already has QoS guarantees.

The diffserv is already supported in WMM, so it seems the more straight-forward approach.

3GPP TS 29.208 V6.6.1 2006-03

3rd Generation Partnership Project,
Technical Specification Group Core Network and Terminals;
End-to-end Quality of Service (QoS) signalling flows (release 6)

This document describes QoS reservation in local IP-CAN for the case of cellular networks. It should not be difficult to adapt it to the WLAN case... the AF and PDF should stay the same... then the SGSN and GGSN should be substited... but for what?

An appendix describes the mapping from SDP parameters to Maximum Authorized parameters

Policy-Based QoS Management Architecture in an Integrated UMTS and WLAN Environment

Wei Zhuang, Yung-Sze Gan,Kok-Jen, and Kee-Chaing Chua

I read it a long time ago, and have re-read it a couple of times since them. It describes some policy-related entities and interactions for wlan-umts internetworking. It can be used as a base, but definetly not as a closed solution. I plan to write a technical report next month. Then it might be converted to an article o can be the basis of my thesis...

ETSI TR 122 934 v6.2.0(2003-09)

Universal Mobile Telecommunications System (UMTS) Feasibility study on 3GPP system to Wireless Local Area Network (WLAN) interworking

It describes differetn scenearios for internetworking, places some requirements, but no technical solutions at all.

Bringing Location Based Services to IP Multimedia Subsystem

Miran Mosmondor, Lea Skorin-Kapov Marko Kovacic

I'm interested in finding out which is the state-of-the-art of collecting, managing and distributing location information in the IMS. This paper presents an architecture that uses SIP mechanisms and the aplication server concept. The application servers ask using a SIP protocol to a centralized entity. This entity interacts with the server that actually contains the location information using MLP.

IMHO, these should not be the way of handling the location information since it should be closely tight to the presence information.

Towards an Innovation Oriented IP Multimedia Subsystem

Gonzalo Camarillo, Tero Kauppinen, Marti Kuparinen, Ignacio Más Ivars

This article proposes a new policy-enforcement mechanism for IMS based on the notify/subscribe methods. This can be very useful to Anna to notify nodes that they must change their codecs.

Experiencing with Blending HTTP, RTSP, and IMS

Sohel Q.Khan, Robert Gaglianello, Michael Luna

SIP, RTSP and HTTP use different networks (I gess this refers to the application level).The author proposes to unify this networks to reduce overall complexity and mainteinance costs.

The 3G IP Multimedia Subsystem (IMS): Merging the Internet and the Cellular Worlds

G Camarillo, MA García-Martín

All ablut SIP, compared to the conventional Internet. Specially intereting was finding that the cell information is actually conveyed in SIP messages. It is also explained how policies are enforced. However, a new policy enforcement technique is detailed in a later article.

Service Delivery Platforms in Practice

Christofer J. Pavlovski

I didn't understand what was the article about. However, I realized an evil use of initialism in which SDP stands for Service Delivery Platform -not session description protocol- and OSS is Operational Support Systems -not open source software.

But there is something useful in the article, the fact that gaming, music and gaming are the most cost-effective services for deployment, so I will probably cite it when I write my journal about location.

TCP Fairness in 802.11e WLANs

D. J. Leith, P. Clifford, D. Malone, and A. Ng

In this article the authors present to unfairness issues in 802.11. First, unfairness between uplink flows due to the irregular delivery of ack packets. And then, the unfairness between uplink and downlink flows because all the downlink flows have to be submitted from de same node (the AP). They already suggest using TXOP to fight this last problem. Concerning the former problem, they propose a separate queue for ACK packets.

Our contribution will be quantify the unfairness by means of simulation, propose TXOP values, and show that the separate queue is unnecessary, since the txop alone is enough to solve the problem.