SMART MOBILE NETWORK

1. SMART MOBILE NETWORK RAJARSHI SANYAL

2. Abbreviations • LTE : Long Term evolution (4G) PATRONISED BY GSMA • IMS: IP Mutimedia Subsystem • MSC: Mobile Switching Center (in 2G / 3G) • CSCF : Call Session Control Function (in IMS) • MME : Mobility Management Entity (in LTE)

3. Evolution of Mobile Communication

4. Key drivers to define the future generation (5G , 6G....) • High Data rate over large coverage areas and dense demographies. • Reduce cost of network infrastructure and operation / maintenance. • Handsets catering next generation applications, less dependence on network , less power consumption. • Less complexity in the Access (radio) and core network layers.

5. The bottlenecks to achieve the objectives with the available technologiesIdea not to bring out the weaknesses of the present, but to focus on improvements. Acknowldege the Unrelented effort of the telecom scientists that we have reached this stage • The Network itself • Hugely complex process of Mobility Management and Radio resource management .Involves lot of control signalling operations between the network elements.Basic philosophy remains the same across all the generations (2G/3G/4G). • Typical hierarchy (cell, location area, network and roaming between networks) • Complexity in radio network design . Network efficiency depends much on the frequency allocation and the frequency reuse pattern defined by the operator.

6. The bottlenecks to achieve the objectives with the available technologies.... • Modulation Scheme : • Starting from BPSK (Binary Phase Shift Keying) in 2G and ending with 64 QAM (Quadrature Amplitude modulation) in LTE -Advanced, we try to trans-receive more symbols per unit of time. • But constrain is the Shannon bound (ref. Shannon law) of the permissible Signal to Noise ratio. The more the data rate, more it is prone to channel impairments and errors. • So in LTE , the handset has to be near to the Base Transreceiver. Augmenting coverage is a costly affair. • Time to look for a smart modulation scheme to realise a smarter network.

7. The bottlenecks to achieve the objectives with the available technologies • Dependence on Layer 7 (application layer according to OSI model) processes : • Network tracks the handset continuously. • Handset initiates a Location Update process in a given time periodicity. • Network and Handset manages the handover to another cell when location is changed.BSSAP,MAP (DIAMETER IN LTE) • All these network activities are managed by Application layer signalling processes at the radio network. • So the Network Equipments and the handset need to be intelligent enough to compute and process continuously the signalling messages for mobility and location management. • The Network equipments should be able to actuate these processor intensive activities , thus increases the cost of overall network . • For the handset as well, it is the same issue as above. Moreover , these processes drain lot of battery power , just to maintain its ‘presence’ in the network. • Signalling messages at the radio layer consumes substantial bandwidth , which could otherwise have been used for data traffic.

8. So our objectives ........ • Render more intelligence to the lower layers so that it can simplify and actuate some processes (like addressing a Mobile Node) , which are today layer 7 functionalities. • Realise a Smart modulation scheme which does not just aim to inject more symbols per unit time. It rather (also) attempts to identify the users at layer 1 (physical layer). • Reduce the Mobility Management and Radio Resource Management functionalities , with a unique Access Network topology which is compatible with this smart modulation scheme.

9. The modulation scheme GSM 2G (BPSK) 3G GSM –UMTS (8PSK) • LTE (16 QAM) • With the evolution of Mobile technology, we attempt to inject more symbols (data) per unit time. • User identification is actuated by higher layers (of OSI) • Our Smart Hierarchical modulation has 2 concentric rings. Outer ring is meant for identifying a user. Inner ring is meant for carrying the traffic for the user .Hence we render intelligence to the physical layer LTE-A (64 QM) Smart Modulation

10. Cell Design Present design Smart network design • The available frequency band is subdivided in Multiple sub frequencies bands. Each frequency is carefully allocated to different cells in the network, taking care that no same frequency is allocated in neighbouring cell. Frequency allocation within all the cells of the network has to be meticulously done. It is hugely a resource intensive activity.In GSM the available bandwidth is divided in 125 sub frequency bands which needs to be allocated carefully to the cells. • Handover of a call which the subscriber is moving from one cell to the other is a process that requires lot of signalling interaction between the handset and the network. Its quite complex. • Simple checker board design. • The available bandwidth is divided in just 2 sub bands (against 125 of them as in GSM). • Square shaped cells • Handover is driven more by the handset and is simplified.

11. Network Design • For a Global Mobile network, we need an intelligent central processor which will act as a bridge between the radio and the core network. • At the core network leg, the intelligent central processor will execute the mobility management ,roaming , authentication , authorisation and other associated network processes by interacting with other network adjuncts. • At the radio network leg, intelligent central processor will be associated with layer 1 &2 level activities and directly take part in analysing the frame at the ingress and help in the frame formation at the egress. • Compared to the complexity we see it is analogous network components of the available technologies (MSC in 2G/3G, CSCF in IMS , MME in LTE) , we can infer that the Intelligent Central Processor is rather a light weight application , as it has to do much less application layer processing.

12. Advantages • Reduces the cost an complexity of network setup and operations. • Makes the handset internal design simpler. Lesser electronics and firmware will make it more affordable. • Makes mobile communication more affordable , which is in turn helps more penetration. • Time to set up a network reduces , as cell / network planning part gets simplified. • As network processes are simplified , more processing power will be available at the handset to fuel next generation intelligent applications.