René Böringer

Evaluation of Mobile IP fast authentication protocol compared to hierarchical mobile IP

Handoff latency affects the service quality of real-time applications. Mobile IP presents the standard mobility management protocol to support the mobility in IP-based systems. However, mobile IP is not adequate for delay sensitive applications. The mobile IP fast authentication protocol (MIFA) is proposed to avoid the problems of mobile IP and to match the requirements of real-time applications. MIFA processes the handoff procedure locally, as is the case with micro mobility management protocols. However, MIFA does not rely on intermediate nodes between the home agent and the foreign agent. Thus, MIFA does not require a hierarchical network architecture as is the case with most micro mobility management protocols, e.g. hierarchical mobile IP (HMIP). A performance analysis shows that MIFA performs similar to HMIP when the mobile node (MN) moves within a domain consisting of two hierarchy levels only and outperforms HMIP otherwise. In this paper we develop an analytical model to analyze MIFA and compare it to HMIP. Our study focuses a comparison of the signaling cost of the two protocols. Our analysis shows that MIFA clearly outperforms HMIP with respect to the packet delivery cost. This is because MIFA eliminates the extra packet delivery cost resulting from the triangular routing that packets experience with HMIP. Additionally, the location update cost when deploying MIFA is comparable to the location update cost using HMIP. Thus MIFA is more effective than HMIP with respect to the total signaling cost.

A QoS-aware Multicast Routing Protocol for Wireless Access Networks

This document describes an approach to integrate Quality of Service-aware multicast into Radio Access Networks (RAN). The protocol, O-MRP (Multicast Tree Optimization-enabled QoS-aware Multicast Routing Protocol) provides fast joining and leaving capabilities to support mobile users. Additionally, the protocol includes a mechanism for multicast route optimization, aiming on different optimization goals, like reduced resource consumption or minimum delay. The flexible integration of both features makes O-MRP outstanding. The approach requires changes to routers within the RAN only. Thus, the protocol is transparent to Mobile Nodes (MN) and network elements outside the RAN, which is an additional major benefit in comparison to other approaches. A simulation study compares the signalling overhead of the multicast protocol as well as the resource consumption with the classical unicast approach, widely used today.

Optimal placement of anchor points within large telecommunication networks

Classical micro-mobility solutions focus on accelerating local handovers and on minimizing signalling traffic. However, the micro-mobility components also slow down the service times in the user traffic domain. This is a critical drawback in terms of the hard delay requirements of future IP-based radio access networks. Network operators need algorithms to determine the optimal number and placement of anchor points within his network to balance both handover latency and user traffic delay. This paper presents a very fast and exact mathematical method for selecting the optimal number and placement of nodes supporting micro-mobility functionality for telecommunication networks. The method is in particular applicable for large networks, which is demonstrated by means of an optimization of a real wireless access network with more than 150 nodes. In order to ensure the applicability in real network scenarios we additionally provide a solution to estimate the stability of the optimal configuration. The presented method allows the autonomous and optimal configuration of the networks micro-mobility functionality as described in concepts of zero-touch networks. Due to the optimization network operators can reduce the administration cost and maximize the quality of service as well.

Optimized I-MPLS: A Fast and Transparent Micro-Mobility-Enabled MPLS Framework

The development trend of mobile communication networks is toward an all-IP architecture. This architecture aims to interconnect the various wireless communication technologies through a common IP core. However, many challenges throughout the development are still not solved. One of these challenges is how to support a fast handover with suitable QoS. In this paper we propose a new architecture for MPLS-based micro mobility management Our proposal called Optimized Integrated-Multi-Protocol Label Switching (Optimized I-MPLS). Optimized I-MPLS is a hierarchical approach to support micro-mobility. This approach integrates the traffic engineering and QoS capabilities of MPLS with Mobile IP Fast Authentication protocol (MIFA) as a mobility management framework. The integration between MPLS and MIFA is achieved through integration of MIFA control messages with MPLS signalling traffic. Our proposal support fast and smooth handoff enhanced with flexible QoS models for down- and uplink streams. The encapsulation overhead for IP-in-IP tunneling is significantly reduced. Additionally, our approach enhances the access security and allows for the stepwise integration in existing networks. The main advantage of the proposal is the transparency for Mobile Nodes (MNs), i.e. the MNs support only MIP, while MPLS will be integrated with MIFA only in the infrastructure.

Comparison of signaling and packet forwarding overhead for HMIP and MIFA

Handoff latency affects the service quality of real-time applications. In this paper we develop an analytical model to analyze the Mobile IP Fast Authentication protocol (MIFA) and compare it to Hierarchical Mobile IP (HMIP). The study compares the signaling costs of the protocols as well as the overall load for packet forwarding. Our study shows that MIFA minimizes the packet delivery cost compared to HMIP. Additionally, MIFA is more efficient when the arrival rate of the packets increases. Thus MIFA outperforms HMIP with respect to signaling cost. From the performance point of view MIFA performs similar to HMIP when the domain consists of two hierarchy levels only, and outperform HMIP otherwise. However, MIFA does not require a hierarchical network architecture as HMIP does.

Using an Extended Anomaly Model to Provide RSVP-Based QOS in Wireless-Lans

The anomaly of WLAN causes a lot of challenges concerning quality of service (QoS) on the wireless link and thus constricts the rollout of new applications and services. The anomaly means that the effective throughput of a WLAN client always depends on the other clients in its cell. This paper describes how to predict the throughput in a WLAN cell based on the number of clients in this cell and their specific automatic rate selection (ARS) rates. Therefore an extended anomaly model is used to compute the throughput at the time. Afterwards it is shown in which way the computed maximum throughput can be used in conjunction with the classical RSVP mechanisms to ensure QoS. The approach is evaluated by a simulation and by a Linux-based implementation in the Wireless Lab as well. Our approach allows providing voice over WLAN (VoWLAN) services even if the mobile clients do not support standardized QoS mechanisms like IEEE 802.11e

QoS in I-MPLS-based heterogeneous networks

The transition to all-IP technology in radio access networks (RAN) results in dramatic changes for the incumbent mobile network operators. In the future, network operators will have to support heterogeneous networks to satisfy customers needs. One of the challenges is to provide end-to-end QoS in heterogeneous networks, e.g. comprising WLANs as well as UMTS. In this paper we propose I-MPLS as a solution to ensure end-to-end QoS in a mixed WLAN-UMTS network. We introduce a transparent and unified QoS signaling scheme and describe the extensions required at the network nodes. In addition, we provide detailed rules on how to map the QoS parameters between the three types of networks