Thursday, 8 September 2016

Next Generation Mobile Networks Evolution with Convergence, Cloud and SDN

TAGS: NGN, HetNet, Cloud, SDN, smallcell, WiFi, offload, mobile core, mobile broadband, wireless networks
Humongous flood of smart devices and next generation applications and also the reach of networking to small piece of appliances the demand of the data traffic is being increased multi-fold on service networks. Networks are no longer remained and will remain an entity of just to provide connectivity but also to understand the whole eco system and have to evolve at every level.
These eco system requirements are coming up with new approaches, generating new challenges and enigmas. To cater these eco system requirements the concept of heterogeneous network at access and unified core network could be evaluated. Where there will be convergence at the access for heterogeneous radios and unified core for the unification of policy, provisioning and mobility.
As devices are already there or coming up with all the new interfaces along with 2G/3G or LTE and WiFi with hotspot2.0 -- Passpoint etc. These technologies are being utilized to provide heterogeneous network connectivity and to be managed to cater the various race and cast of traffic that the devices generate, depending on the services and connectivity.
This will not only provide the capacity enhancement but also efficiency of individual access network connectivity. It will result in total convergence at radio access and there would be selection mechanism to decide the network at access for specific service and related traffic forwarding to and from core network which is providing public network connectivity.
The complexities which will arise on such network evolution would be for the demand for flexibility, elasticity, unification, ubiquitous and seamlessness. The feasibility of addressing such requirements lies in the paradigm shift of complete separation of control and data plane and in such endeavour cloud and SDN are going to provide encouraging enabler. In such endeavour the control plane would fall to cloud and data plane would be on SDN.
Coming to more specifics on network architecture, Access stratum and non-access stratum (core) paradigm is going to hold with such enhancements. As access stratum would be more about access selection and capability associations etc. whereas core would be more on service delivery, policy, mobility and network connectivity.
on mobility front also shift will happen from hierarchical mobility to network mobility and hierarchical mobility will stand with the best limited reach at access stratum. That means to say that IETF protocols may dominates in the whole mobility aspects of the systems.
While looking at the upcoming thrust and compulsion for evolution in network architecture, a solution approach for the same could be contemplated. This is briefly defined as convergence at access stratum, and non-access stratum with unified core where an  ‘Access Controller Agent’ will help to select the access network and also will construct the core by finding the required association of cloud and SDN. The figure below depicts the emerging mechanism.
 The separation of control plane and data plane in next generation mobile core network architecture has already happened to some extent in EPS or SAE. Thanks to All IP paradigm in mobile networks to make this happing. Coming of cloud and SDN is going to corroborate this paradigm shift to further extent.
As depicted in the Figure the access will be approaching to unified core through globally unique network service access identifier (NSAPI), which will be helping to find the right Access controller agent to find association between cloud for control plane and SDN realm for data plane. Agent is a variant of MME as most of the MME functionality will move to cloud it would be there with global attributes and domain specific scope to land to right cloud and enter into right SDN realm or domain. The networks of agents would provide the unification of policy and provisioning and mobility.
This paradigm shift which I refer to as “homogenous connectivity of heterogeneous networks” could be envisioned to transform the next generation network architecture to suit the emerging eco system.