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 UNS integrates 3G, WLAN and high-Performance IP GIGA STREAM is announcing its Universal Navigation Switch (UNS) platform and is setting the pace in the design of voice, data and video service nodes for next-generation wireless networks that will be the life-blood of 3G and WLAN / WiFi service offerings. The UNS facilitates a smooth migration from the current TDM, ATM transport towards all-IP internetworking.
The Mobile operators spent a great deal of money on 3G licenses and are now finding it increasingly difficult to create applications that will satisfy their customers let alone make a profit. They built-up mobile infrastructure - in order to comply with regulatory requirements - that resulted in a complex set of network equipment. This has become difficult to manage and to maintain during operation and the introduction of new services and applications is, in consequence, a very expensive and time-consuming task.
The UNS network switch will dramatically reduce the complexity and integration effort for mobile operators. It will increase the adoption rate of new applications thus satisfying end-user demand. It will also centralize operational functions and add value with the integration of the various networks and topologies into a single platform. This will ensure full, seamless interworking of all wireless and Internet technologies.
"Such an integration task won't happen overnight", says Thomas Maul, Founder and CEO of GIGA STREAM: "For this reason we have chosen a 4 phase plan. The initial phase, implemented in most GSM networks today, took care of the introduction of data into voice centric mobile networks. With the official presentation of the UNS platform at the Telecoms 2003 Show in Geneva, GIGA STREAM sets the pace with the integration of the various wireless access technologies and the optimization of the mobile core network. This is the right time to introduce UNS. Mobile operators clearly understand the value of UNS integration capabilities."
How the UNS works Switching functionality is divided into two elements: a control plane comprising the routing algorithms and call control, and an intelligent transport plane that establishes and maintains the voice and data paths. GIGA STREAM's exclusive content sensitive traffic management (CSTM) provides full application-aware visibility into network traffic, facilitating new high value business and consumer applications including customized services, SLAs, location based services, alternative billing methods and seamless roaming between Radio Access Networks and WLANs.
The UNS platform is designed with IPv6 and MPLS in mind. The topology modules provide connectivity to Gigabit Ethernet, ATM and E1 with support for SS7 signalling. The solution is designed for today's 3GPP standards based on ATM in the RAN (radio access Network) and core network, but can be easily upgraded to an all-IP core.
The Operator Benefits Because the integration and functionality is on a single platform, dramatic cost savings can be achieved - up to 70% in capital expenditure and up to 50% in operating expenses, as compared with multi-component switching products. Single-platform integration also greatly simplifies capacity planning, security and network management. And service delivery may be direct or via Virtual Operators so that carriers may sell-on their excess capacity.
Accelerated time-to-market and enhanced competitiveness are additional benefits thanks to advanced features such as seamless interworking, intelligent routing, and support for innovative billing models individualized by subscriber, service type and usage. And the UNS switches are scalable up to the highest speeds - and capacities so operators can start small and expand as needed.
The Ultimate Mobile Objective "Having seen the convergence of voice, data and video in the wired world, 3G and WLAN are now bringing broadband technology into the wireless world. The UNS switch will be the enabler to facilitate a controlled migration,"
"WLAN hotspots provide an effective but highly localized solution - you'd need a new antenna every 15 meters to allow the user to roam, whereas 3G covers several square miles per antenna. By providing a seamless integration between them, the UNS will enable the WLAN to complement 3G, with the user able to move back and forth between the two, once having established a session in either,"
.BT's 21st Century Network Building the World's Biggest Next Generation Network This EXAMPLE will provide a technical case study on BT's next generation network (21CN), one of the world's largest and most advanced MPLS/IP/Ethernet networks. In June 2004, BT publicly announced it was going to be the world's first national telecoms operator to take the bold step of replacing its entire existing legacy network infrastructure with a next generation network built using MPLS, IP and Ethernet. The plan announced was that by 2010 BT's 16 legacy networks (PSTN, ATM, PDH, Frame Relay, TDM, etc) would no long exist, they would be replaced by a single, national IP/MPLS,/Ethernet network. 21CN must support not just next generation services such as triple play and video on demand, it must also support traditional legacy services such as emergency services private circuits and the UK's national public switched telephony network. It must be a truly national network, covering all locations from remote rural to major cities. It must support the requirements of over 30 million customers, from the residential subscriber to largest corporate. It must support all services, from those requiring simple best effort, to those requiring over 99.9999% availability, delivery, and performance guarantees, and it must enable any communications services provider to connect into it seamlessly. To meet all of these criteria, BT is pushing the envelope of MPLS networking to the very limits of its capabilities, and in some cases beyond what can be delivered today. From day one, 21CN is supporting Graceful Restart (RFC3623, 3478, 3473) for all routing and MPLS protocols, pseudo wires (RFC3916), IP VPNs (RFC 4364), MPLS Fast ReRoute (RFC4090), and 8 levels of QoS. Because 21CN is the UK's next generation network national infrastructure it is carrier grade and industrialized, with the scalability, flexibility, resilience and robustness to support any application, at any grade of service, to any location across the UK. If 21CN fails to meet these very stringent requirements, the consequences could be catastrophic for residential, private and public sector businesses.
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.
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