World Wide Wireless Web.-Part 3. Integration of MPLS with 3G/4G, WLAN and other wireless technologies.
During last couple of years, cellular systems have becomes one of the most popular wirelesses Communication mediums. But in the hot spot region use of WLAN has increased due to its high data rate and low installation cost. The recent growth in the worldwide usage of networking technologies has posed several questions and brought new opportunities to the research and academic community. The developments in these technologies have occurred independent from one another. This has limited the interoperability of various systems. On the other hand, due to e-commerce and other interesting new applications of the networking technologies, the user is attracted to subscribing more than one type of services, such as wireless Internet, multimedia, global positioning systems, etc. However, there is a need of integration of these technologies from an inter-operability point of view. This need seems to be best met by defining international common goals that could be used as guidelines for designer and vendors of such technologies. 1. INTRODUCTION In this paper, we present an integration of GPRS/3G/4G and WLAN in connection with Multi protocol label switching (MPLS). The mobility is managed by hierarchical mobile IPv6 (HMIPv6). The aim of this paper is to look at seamless mobility with low signaling overhead and provision for optimal quality of service (QoS)
Wireless networks are projected to integrate not only the services (to provide multimedia), but also encompass an integration of technologies. The technology integration has two aspects, namely, the integration of the same technology from different parts of the world, and secondly, the integration of different technologies in the same country.(3G) wireless systems are working diligently to realize the integration of various Code Division Multiple Access (CDMA) standards. Similarly, IP services with CDMA, integration of CDMA air-interface with other wireless access networks, such as wireless LANs, wireless ATM, fixed wireless broadband Internet access are all proceeding at a rapid pace. In other words, a user with a terminal and a single subscription may have access to any or all services that multimedia mobile data networks have to offer.
Technically, there are many ways in which these integration goals can be achieved. One (almost traditional) approach is to have one-to-one interface between any two different technologies at a fixed point and allow all traffic to pass though this point for a 'protocol conversion'. An example of this is the use of ATM Adaptation Layers (AALs) to carry IP and telephone traffics over an ATM backbone. AAL provides a separate interface between each type of higher layer above the backbone network. All traffic is switched end-to-end via the ATM switches in this case.
A second approach of the technology integration is to allow all traffics share the network resources and incorporate some sort of multiple label switching. This approach places the design complexity in a switching device with a signaling additive, and liberates the traffic from delays for protocol conversion. An example of this approach is the Internet's multiple protocol labels switching (MPLS). This approach is already proving to be agreeable among the research and industrial community and has the exclusive benefit of reducing processing over packets of data - much desirable for multimedia traffic. The input and output links to the switch, are shared by all traffic types. When a packet enters the switch, a label-processing block first determines the packet type (IP, ATM, Wireless, Etc.). The label processor then directs the packet to one of the planes labeled as Wireless, IP and ATM depending upon the label on the packet. Each one of these planes performs routing according to a different principle. For example, ATM routing is based on virtual circuit identifier or virtual path identifier (VCI/VPI). Similarly, IP routing is of store-and-forward nature, while a wireless network may provide a mixture of the two. In this way, the switching and routing delay experienced by a packet in the switch depends on its network type.
Future research may have to expand the scope of MPLS concept to bring it at the access node of a network. Let us look at the limitations of Wireless Networks
BELOW ARE SOME BEGINNINGS OF FORAY INTO COMPLETE WIRELESS INTEGERATION
GMPLS-based Multi-Layer Network (GMPLS-MLN) Concepts, Architecture and Services Kohei Shiomoto, NTT GMPLS-based multi-layer networks (GMPLS-MLN) is a promising technology to provide integrated control of packet and optical layers in service providers' networks [MLN-REQ, MLN-EVAL]. This presentation reviews concepts, architecture, and services of the GMPLS-MLN. In this presentation, we start by reviewing the concepts and basic architecture of GMPLS-MLN. In the GMPLS-MLN, client networks, e.g. routers, are supported by a server network, e.g. OXCs and ROADMs, using a multi-layer GMPLS control plane. We demonstrate the flexibility of the control architecture by defining three interworking control models between client and server networks: overlay, peer, and augmented models. We then describe how these models address the architecture requirements of GMPLS-MLN. We discuss various factors influencing the architecture choice, including the following: - Trust model between the packet and optical networks. - Scalability requirements - Resource utilization, traffic engineering scope (single layer TE, multi-layer TE) - Deployment aspects - Fault recovery and stability We discuss how the proposed models can be realized using existing GMPLS protocol mechanisms and potential extensions to the GMPLS protocols, including key concepts such as ISC, FA-LSP, Virtual TE-link, and VNT. We conclude by describing how network services can be provided for client networks using a GMPLS-MLN. An IP/MPLS network is discussed as an example of a client network. The vertical and horizontal relationships for the data plane, control plane, and service plane are described. [MLN-REQ] Requirements for GMPLS-based multi-region and multi-layer networks (MRN/MLN) (work in progress), January 2006. [MLN-EVAL] Evaluation of existing GMPLS Protocols against Multi Layer and Multi Region Networks (MLN/MRN), , January 2006 Back to top Multi-Layer Models: IETF vs. ASON/OIF Lyndon Ong, Ciena Work on multi-layer networks is still in progress for ASON. This talk discusses some recent activities within the ASON standardization efforts to support control of multiple layer networks. In particular, issues related to multi-layer discovery and routing are addressed.
Neighbor discovery allows automated identification of neighbors and exchange of link characteristics separately for different layers, and requires discovery mechanisms that can be applied at different layers. ITU-T defined transport network layers generally provide some associated control channel capability that aids the process of neighbor discovery. For SONET/SDH, for example, there are the J0 and other overhead bytes as well as the DCC communications channel. For OTN, there is the GCC communications channel that is part of the overhead for electronic OTN signals, as well as the Optical Supervisory Channel that is defined as a part of the photonic Och signal. ITU-T G.7714.1 defines a mechanism for communicating neighbor identity over each layer device interface. While neighbor discovery could be performed at each layer, this is not necessarily the most optimal way to perform discovery. Indeed, performing neighbor discovery at each layer would require the use of multiple discovery messages to be transmitted and the results would have to be coordinated across all the layers. A simpler solution is to perform neighbor discovery at the lowest layer of the link and then advertise the various adaptations used at each end of the link by messages sent over the control channel as a part of Transport Capability Exchange.
Routing similarly is assumed to take place independently for each layer network, however the routing protocol may support the inclusion of information for multiple layers in a single message or object. Static server layer connections are assumed to be in place to support client layer traffic and are reflected in the routing advertisements at the client layer, similarly to the "Virtual Network Topology" approach. Traffic analysis to derive the optimal server layer topology is assumed to be an offline process. Dynamic routing may also be possible using the abstraction capability in ASON routing to advertise a simplified model of potential reachability at the server layer to those nodes that support adaptation from client layer to server layer transport and can then request the server layer to instantiate new real connectivity to meet a new traffic demand
Recently the concept of PCE has been added to ASON routing (some would say it was implicitly there from the beginning) and a separate Recommendation is being created describing PCE architecture and requirements. PCE may be another avenue for addressing more dynamic multi-layer routing issues.
GMPLS Network Design Considering it's Control/Data Plane Resiliency Tomohiro Otani & Kenichi Ogaki, KDDI R&D Lab This presentation describes the guideline of designing the IP-based data-communication network (DCN) for the GMPLS out-of-band control plane from the point of actual network deployment considering the evaluated results of the control plane resiliency and scalability The IP-based DCN for the GMPLS control plane requires high availability without affecting the control plane operation by using, for example, fast convergence of routing and the bandwidth enough to convey control packets. However, as the various protocols on the GMPLS control plane and the DCN are complexly interacted with each other, the evaluation assuming an actual environment is indispensable in addition to the theoretical analysis. We utilized the testbed consisting of actual elements such as GMPLS capable routers, PXCs and WDM equipment with hundreds of kilometers transmission line in our laboratory environment. Although the disjointedness of SRLG must be considered between the control plane and the data plane, such disjointedness may not be completely ensured under the actual network environment. Therefore, as the worst case, both control and data planes between two sites are configured through the same transmission line. Firstly, the influence with resiliency in the IP-DCN to the GMPLS control plane was evaluated by the fast IGP failure detection mechanism of BFD. By speeding the convergence up to several hundred milliseconds by BFD, the LMP session as well as GMPLS neighbors could be maintained, and other GMPLS operations were not consequently affected except for the extra-restoration time due to the DCN routing convergence. Furthermore, the scalability of the GMPLS control plane over the IP-based DCN was evaluated by adding emulated nodes from a network tester, assuming that the GMPLS network scale grows. The traffic flow over a physical link of the DCN accommodating control channels between two sites were measured at the moment of the OSPF initial database synchronization by enlarging the network scale up to a few hundreds nodes. Traffic increase was much smaller than the GbE line bandwidth used in the DCN and it is verified that the bandwidth of even Fast Ethernet will be acceptable. The more detailed results will be presented in the conference, including data plane and control plane interaction effect, and those series of evaluation is quite useful for the deployment of GMPLS commercial networks.
Conclusion: The 3G cellular networks, e.g. UMTS are designed to provide users with voice and data services. Total cell capacity limits the per user data rate. Many times highspeed requirements are clustered in small pockets. These clusters are termed as hot-spots. Network operators would like to employ efficient solutions, which are easily integrated with their existing UMTS, based infrastructure.WLANs offer an attractive solution. 3G cellular accesses based on code division multiple access (CDMA) either wideband CDMA or cdma2000 can be used to satisfy users who have a larger need for mobility while 802.11 systems can be used to support users with much lesser coverage area requirements. It is in light of this, the next wave of technological advance is already under consideration i.e. 4G. Several International projects are already underway to ensure that services are suited to the characteristics of several different delivery mechanisms, from cable networks to GPRS networks, and the services can be delivered using the most appropriate of the range of networks available. In addition the dynamic allocation of available spectrum between different wireless networks is also under investigation. The challenge is to explore the design of such a transport infrastructure which will be able to take full advantage of IP based technologies achieving desired mobility between the various access techniques and at the same time provide the necessary capabilities in terms of QoS, robustness and manageability. The goals at the present stage regarding the development of mobile standards remains common (3GPP and 3GPP2) and include IP based multimedia services, IP based transport and the integration of IETF protocols for functions such as wide area mobility support (MIP) , signaling (SIP) and authentication, authorization and accounting (AAA), it is popular to call any network that satisfies these criteria as an all-IP network.
