Abstract-We present a scheme for flow management with heterogeneous access technologies available indoors and in a campus network such as GPRS, 3G and Wi-Fi. Statistical learning is used as a key for optimizing a target variable namely video quality of experience (QoE). First we analyze the data using passive measurements to determine relationships between parameters and their impact on the main performance indicator, video Quality of Experience (QoE). The derived weights are used for performing prediction in every discrete time interval of our designed autonomic control loop to know approximately the QoE in the next time interval and perform a switch to another access technology if it yields a better QoE level. This user-perspective performance optimization is in line with operator and service provider goals. QoE performance models for slow vehicular and pedestrian speeds for Wi-Fi and 3G are derived and compared.

Abstract-An Open Access Network (OAN) is characterized by the fact that private WLANs and broadband access lines are made available for public use, enabling bypassing mobile users to profit from continuous coverage. Our insight is that in wireless OANs, the overhead required for the launching or reconfiguration of a real-time session can be drastically reduced. We propose an algorithm which performs parameter injection into a multimedia data stream instead of following the classical negotiation path typically used. A solution to change the session characteristics of an application that adapts to varying network conditions was developed, including a QoS solution with SIP and MIP to optimize the session characteristics by taking into account the changed conditions in the network. With our approach, we achieve a reduction of a factor of 2.5 for session signaling delay, and excellent jitter values in the range of 10-15 milliseconds as our implementation results show.

In this paper we look at the signaling for session mobility using the Session Initiation Protocol (SIP) and the Session Description Protocol (SDP). Bearing in mind that perceived voice quality is sensitive mostly to delay variation (also called jitter), we work on bounding that value for providing a better voice Quality of Service over Wireless LAN (WLAN). For mobility we use a hybrid SIP-MIP stack. The basic idea is to combine the strengths of MIP for doing fast handovers and the strengths of SIP for powerful session adaptation capabilities. Numerical calculation figures as well as real implementation results are provided. It can be observed that the session update cycle during mobility can be modified in such a way that session delay variation bounds achieved are quite low and there are almost no spikes. We use composite performance metrics that we defined in previous work to analyze the correlation between the data patterns for session signaling delay in the classical case and our proposed case to better highlight the achieved performance delta.

An important feature of the upcoming fourth generation wireless networks is support for heterogeneous radio access technologies in combination with an all-IP type of overall architecture. Operators and users will benefit from a smooth technology transition leveraging existing investments and use a variety of access technologies simultaneously. This paper describes and evaluates an innovative mobility management scheme in such an environment. It does not require any changes to the IP stack in the mobile node and does not introduce any additional overhead to the payload traffic over air interfaces. Furthermore, it does not add any signaling overhead and outperforms existing mobility management schemes for heterogeneous environments in terms of bandwidth consumption. The architecture uses a make-before-break principle for vertical handovers and bidirectional tunneling using various tunneling mechanisms connecting mobile nodes through access networks to a home network. Also, it proposes a packet inspection routine for timely handover execution in the home network. The architecture is evaluated both through analytical calculations and experiments using a voice over IP traffic model.

Abstract-Starting with an efficient mobility management scheme for heterogeneous wireless networks, this paper proposes a solution for AAA handling using a common database for storing user information. Regardless of the access technology selected, user@realm identities are used for authentication, authorization, and accounting. In particular, a new function is introduced in which port-based network access control is used in combination with dynamic host configuration protocol mechanisms for IP address allocation. This way, PPP-based and Ethernet-based access technologies are handled uniformly.Advantages with the proposed solution include: using only standardized mechanisms in the mobile node, as well as in the access networks. Only an additional plug-in in the AAA server (located in the access networks) needs to be deployed.The proposed AAA architecture has been implemented and evaluated in a live experimental environment. Results show authentication and authorization to perform efficiently and seamlessly.