The role of virtualisation in the dense wireless networks of the future Sokol Kosta CINI

Distributed Computing, Storage, and Radio Resource Allocation over Cooperative Femtocells

3 Increasing demands in the wireless world Want it all! Want it here! Want it now! Can we enrich users experience with today’s terminals? Well, it is all about apps… Backhaul and wireless

4 Current elements in modernization of applications According to CISCO 1.Make them accessible over the Internet on any device anywhere 2.Enhance performance, resilience and throughput 3.Use cloud computing for faster time-to-market, continuous development and change 4.Leverage open source components and open APIs 5.Develop and execute on infrastructure shared by multiple applications and users TROPIC encompasses these targets and goes beyond…

5 Overall TROPIC objectives TROPIC redefines architectures able to… …virtualise/distribute applications close to user at empowered smallcell base stations …enhance physical layer performance Bringing computational power closer to users will entail 1. improving user experience, 2. prolong UE battery lifetime, and 3. potential revenue stream for operators

6 Small cell manager The TROPIC scenario

7 Offloading to small cell eNB: pros and cons Running apps in empowered small cell eNB instead of external cloud Running apps in empowered small cell eNB instead of UE Small Cell Manager + Reduced latency + Reduce usage of backhaul - Management of virtual machines + Computation speed + Reduced battery consumption -Management of parallelization -Increased PHY utilization Small cell manager (SCM) is needed to allocate computational resources

Technical scenarios SCM serving single cell SCM serving multiple cells Coexistence of multiple SCM and cells

9 Small Cell Manager (SCM) provides offloading support to the UE, including computation/storage/radio resource management Best network architecture may differ among Mobile Network Operators (MNO), and may depend on the scenario (corporate, public, residential) Network architecture needs to be enhanced

10 Joint management of radio and computational resources Latency budget: Bits processed, communicated from/to UE Time for UL and DL wireless tx Energy budget: Parallel processing Energy spent in ULEnergy spent in DL Both convex problems with unique solution It is possible to plug an abstration of the PHY layer, for MIMO or even MU-MIMO channels

11 -Given latency and battery contraints, we can select a different operation point -Each combination of application, processing architecture, and radio tx scheme will generate a different curve SNR DL =SNR UL = 20 dB Energy vs. Latency Tradeoff Example for virus scan application…

12 … in a multiuser scenario UL UL Remote comp. resources DL UL scheduler Computation scheduler DL scheduler If multiple users are served by a single FAP, combine energy-latency resource allocation with scheduling policies.

Benefits and potential hurdles 13 Potential hurdles… Additional investment by MNO Best network architecture may differ among MNO, and may depend on the scenario (corporate, public, residential) Improving user experience, Prolong UE battery lifetime, and Potential revenue stream for operators Benefits

Connectivity management for eneRgy Optimised Wireless Dense networks

Goal of CROWD To enable sustainable deployment of very dense and heterogeneous wireless networks sustainable = cost effective + energy efficient very dense = 1000x compared to current density (in users/sqm vs. users/BS) heterogeneous = + diverse range (macro vs. pico vs. femto) + diverse technologies (LTE vs. WiFi) + diverse deployments (planned vs. unplanned) + diverse backhaul types (optical vs. wireless)

Research challenges Very high density + heterogeneity = 1. Interference in the radio access network 2. Poor efficiency in the backhaul 3. High signalling for traffic management

Interference Issues with increasing density to grow capacity: OPEX : limiting factor, no automated tool for HetNets CAPEX : base stations are complex & expensive Capacity does not scale with base station density!! Some inter-cell cooperation tools are available ABSF (LTE), OBSS (802.11) Control tools needed  CROWD Control architecture Increasing number of eNBs provides an increasing of capacity up to a limit. Indiscriminate increase of network density is not a viable solution

Backhaul Increased capacity demand and density has to be sustained by the backhaul network, not only by the radio access network → pitfall: costly overprovisioning of the backhaul network CAPEX: expensive high capacity backhaul equipment OPEX: increased cost and energy waste Dynamic provisioning of backhaul resources is the key to an efficient backhaul operation in very dense networks

Signalling 1.Technology-specific issues, e.g.: – 70% of air time (WLAN) occupied by management frames – Most of air time is taken by scanning processes 2.Mobility-related signaling critical: – Very frequent handovers, lots of subscribers – Reduce signaling over the air, Proxy approaches

CROWD Architecture Logical view

Business view

The role of virtualisation in the dense wireless networks of the future Sokol Kosta CINI