Key drivers to Next Generation Networks

The three main factors that will affect the technological developments
and standards for NGN include service portability, access independence
and packet behavior. BALAJI HOLUR demystifies the dynamics of these
key variables…

Balaji Holur is currently the Director of the Cellular Systems Division at Texas Instruments India responsible for chip solution developments for new generation mobile handsets. His area of expertise is wireless systems and networking. He holds M.Tech. and M.S degrees from Indian Institute of Technology Kanpur and Okalhama State University respectively. He has around 20 years of experience working with companies like Nortel, Cisco and Samsung prior to joining TI in 2005. He was the architect and founding engineer of a highly successful startup IpMobile which was bought over by Cisco.

Next Generation Networks (NGN) are packetbased networks that can provide services including Telecommunication Services and can make use of multiple broadband, QoS-enabled transport technologies and in which service-related functions are independent from underlying transport-related technologies. According to ITU, they offer unrestricted access by users to different service providers. It supports generalized mobility which will allow consistent and ubiquitous provision of services to users.

The following have been the key driving factors for NGN:

1. Users may have access to networks of different technologies with communication across networks of identical / different technologies but retain a desire to be "always best connected" - aiming at availing a wide spectrum of services
2. Growth of the Internet and other IP-based networks with their requirements for bandwidth and capacity has driven rapid innovation in telecommunication access and transport networks
3. Ongoing trend towards integration and interoperability of IP-based and PSTN network services and applications to unified Next Generation Networks providing both Internet and carrier-grade telecommunication networks and service offerings with
   QoS to anybody, anytime, anywhere.

The three main factors that will affect the technological developments and standards for NGN include:

• service portability
• access independence
• packet behavior

Service Portability
We are getting into an era where the user perception of a service is that his range of services should be oblivious of the networks or domains that he gets into. In effect, it means that whether you go
from a circuit-switched network or a packet-switched network or the 3G or 4G network, it's all going to be based on the user perception of the services and that they should be portable across all media.

With the inevitability of convergence of networks, we can talk about the ad hoc networks, the micro networks and the macro networks. One of the classic activities that is currently happening is the integration
of the WLAN convergence with the 2.5G or 3G networks; so by having a terminal or an end -user device, one can have the capability to access both the wireless LANs and the 2.5 G network (or 3G network).
Discussions have already started on integration with the wireless broadband (WiMAX) kind of networks.

Such portability allows one to seamlessly move from the macro area (2.5G or 3G network) into a hotspot (a micro area) and experience a wide array of services. More critically, one should be able to experience the same services whether in a macro area or a micro area. Further, extensions would allow users to 'create' ad hoc networks on their own depending on the level of services that they have chosen and the locations they work/reside in. Basically the consumers of these NGN or convergent technology-enabled devices should be able to seamlessly move across any kind of networks with unified services and common billing.

The following is a brief summary of service characteristics in the NGN environment:

• Ubiquitous, real-time, multi-media communications transport for any medium, anytime, anywhere, and in any volume
• More "network and personal intelligence" distributed throughout the network
• Personal service customization and management.

Accordingly, the service portability provided by the relevant service providers of the users will become very important and will adhere to the main goal of third generation technology in providing universal personal communication. Regulators have developed a regime based on existing services' markets, and have promoted competition mainly through interconnect, based on cost-oriented prices. NGN create new cost
structures, network designs and service interfaces.

Once standards come in, there might be a realignment of competitive tariffs structures, revenue sharing models and market alliances. As networks coalesce across boundaries and an emerging class of consumers are ready to avail services irrespective of geographical confines emerges, it is only a matter of time before global service providers have their alliances in place to ensure seamless mobility for their customers.

Packet -Based Systems
Initially, when phones were introduced, they had circuit behavior in terms of how calls were made or how information or data was exchanged. Unfortunately, even 2.5G networks have circuit behavior. All the packets that have been introduced during the last 3-4 years are nothing but an extension of the circuit behavior in the packet domain. So if one looks at the current deployment on the network side, perhaps all the packet nodes that have been implemented work with circuit domain, hampering network expansion.

Supporting reliable, real-time services is a decisive factor for the increasing migration toward packetbased mobile networks. The complementary characteristics of IEEE 802.11 technology- based Wireless Local Area Networks (WLANs) with faster short-distance access and 3G networks with slower long-range access make it attractive to integrate them to provide ubiquitous wireless access. The Third Generation
Partnership Project (3GPP) has initiated the development of a 3G-WLAN interworking architecture to allow 3G service providers to offload data traffic from wide area wireless spectrum to WLANs in indoor locations, hotspots, and other areas with high user density. The subscribers benefit from enhanced performance through greater coverage, higher data rate, and lower overall cost from the interworking service.

As the 3G-WLAN interworking evolves into a ubiquitous communication infrastructure and provides various services, the advent of real-time multimedia traffic gives service providers a tremendous opportunity to offer both traditional services as well as a wide range of creative new services that integrate voice communications with data applications and exploit the power of intelligent end terminals. However, there are substantial challenges in supporting and providing guaranteed good quality real-time services, while preserving user privacy and also to support a large number of users without compromising voice quality.

To be sure, packetization will make a big impact in terms of performance, throughput and the evolving connectivity that is being witnessed. The very idea is to develop deeper capabilities in order to capture digital data, translate that into IP packets and send them across networks. That is why, when one looks at the long-term evolution of the standards in wireless broadband (e.g. WiMAX); the desire is to push IP-termination to the edge of the networks so that ideally there will be real packet behavior in the entire network rather than a combination of packets and switches. It is, however, unrealistic to expect a totally packet-based environment at least in the next three years as existing investments have to be recovered in 2.5G and 3G systems.

In the near future, with the migration to packet networks from circuit-switched networks, there will be more packet-based billing. Immediate market needs for the System-on-Chip (SoC) have to be addressed. The key is to upsell services as much as possible because the underlying behavior of the chipremains the same. Only the features related to power, performance, size, battery life etc. may need to be managed. The design roadmap for chips would be driven by installing/loading of applications that may be used by the end-users. This is where the key differentiating variables will come into the picture in predicting market trends and consumer behavior for the low-end, the mid-tier or the high-end market. Retooling of the manufacturing line, the only way to survive in the demanding marketplace, will call for very prudent planning. It would require being familiar with the changing and dynamic market conditions, evolving technologies, access devices with concomitant adjusting of plans and strategies.

Access Independence
Will complete packetization affect the performance and 'navigability' of access devices? Moreover, will there be access independence that is the key to the very adoption of any kind of NGN devices? The answers to these questions will shape the development and adoption of the NGN devices. All the service providers and handset players will have to envision the heterogeneity in terms of formation of various macro, micro and ad hoc networks and then allow for seamless movement of users across these networks. Subsequently, applications and features need to be bundled which are then made compatible across networks, domains and even devices.

They will have to account for house and office convergence of systems and related "components" and arrive at the right kind of alliances and collaboration to ensure access independence for anyone at anytime, anywhere. The future of NGN devices is dependent on a number of scenarios, market dynamics and evolving standards but the endpoint will be a bouquet of seamless services for end customers.