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6 lte-a challenges and evolving lte network architecture

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  • 1. LTE-A Challenges and Evolving LTE Network Architecture Mobile and Cloud Infrastructure Convergence Munish Chhabra - Aricent November 2013
  • 2. Agenda LTE-Advanced and HetNets Challenges Evolving LTE Network Architectures Summary Proprietary & Confidential. Aricent Group 2013 2
  • 3. LTE A & HetNets 3
  • 4. Challenges.
  • 5. Network Densification Necessity to achieve desired capacity First Step: Coverage (Macros) Next Step: Capacity (HetNets) Bring network closer to the user More radio links, more antennas, higher spectral efficiency LTE Advanced + HetNets -> Take capacity gains to the next level 5
  • 6. Network Densification (Contd) But, More Base Stations lead to More Capex Equipment (baseband, radio, antennas) at each site Shelter, Air Conditioning, Battery at each site Backhaul Connectivity with core network (cost vs performance) Increased Opex More Rental and running cost More trained staff for network planning and maintenence More site visits for preventive and fault handling Energy Efficiency Significant part of OPEX Included Market, regulatory and customer requirements (especially for small cells) Interoperability Interworking nodes between different networks A tier-1 operator in Europe typically spends around 60% of revenue in OPEX. The burden will surely increase with LTE and LTE-A 6
  • 7. Network Manageability The number of network nodes go-up exponentially Besides they co-exist with multiple other RATs Extremely challenging to maintain and optimize such networks e.g. # Neighbor Relationships grow exponentially # Handover Relationships grow exponentially Coverage / Capacity trade-offs between different network layers Interference management becomes even more challenging Dynamic traffic patterns and low base station utilization Residential areas in the evening, Commercial during the day 7
  • 8. The Backhaul Challenge Increasing radio network complexity casts its shadow on the backhaul More base stations, more backhaul links Base stations differ in terms of capacity, reach, transmission power and radio access network technology, including 3G, 4G and Wi-Fi Puts additional complexity burden on backhaul ICIC and CoMP (Coordinated Multipoint) Needed for better user experience at cell edge ICIC Coordination of spectrum allocation across multiple cells CoMP - Multiple base stations simultaneously serve a user device Needed - Real time co-ordination between base stations Needed - Low latency on backhaul Base station need sub-frame level co-ordination Clocks need to be in phase Common reference needed from backhaul 8
  • 9. User Device Challenge Carrier Aggregation UE to handle multiple simultaneous transcievers Contiguous and non-contiguous carriers may be aggregated Challenging radio environment MIMO Up to 8 transmitters in DL MIMO increases the number of system antennas Design of Radio antennas supporting Multiband and MIMO In the tiny space on a UE Becomes extremely challengig Battery life of devices 9
  • 10. Interference Management Higher base station density, more Interference Randomly distributed Difficult to control and maintain coverage area, tilt, power and placement of small form factor base stations Particularly difficult to optimize Cell Edge users performance Terminal assigned to macro, sees strong interference from micro Especially if micro serves a CSG and the UE is not allowed to latch on to it 10
  • 11. WiFi and Offload Considerations Almost ubiquitous availability of WiFi (especially indoors in homes and offices) mandates it for operators to consider offload Offload however comes with its own challenges that have no answer in the specifications yet Pre-mature WiFi selection Improper choices Degraded QoS after movement to WiFi Managing Trusted/Non-trusted networks Ping-pong problem 11
  • 12. Evolving LTE Network Architectures
  • 13. Telco SDN The Next Wave Mobile Networks Then Mobile Networks Now SDN A network of point-topoint connections A programmable fabric that can be manipulated in real time to meet the needs of the applications and systems that sit on top of it SDN would mean Network virtualization - Implementing more in software and using commoditized IT hardware Programmability - The ability to centrally change traffic flows, partition the networks and provide application-level QoS. Separation of control and data plane Source: 13
  • 14. SDN Example Ref: 14
  • 15. Cloud RAN Specific SDN use-case for the RAN Cloud RAN The first implementation of virtualization in RAN layer Separates the computing intensive baseband processing from the remote radio deployments Baseband processing is pooled at a semi-centralized location C-RAN Enables Use of commodity HW to run baseband processing tasks More fluid resource allocation. Enables new feature implementation like CoMP and eICIC Helps ease capacity crunch by placing radios closer to the user 15
  • 16. Cloud RAN Architecture Possibilities Active Antenna System Centralized Baseband Bank 2G/2.5 G UMTS HSPA SON Server LTE eNB LTE-A Common Management Server IMS/ Operator Services Optical IP Remote Radio Head Internet Coax IP Macro Site IP Femto Cells/ Wi-Fi IP Controllers RAN SERVERS on the GSM/GPRS cloud UMTS UMTS Femto GW HeNBGW Wi Fi Access Gateway Core Network Services are provided through optimum access technology Resources and coverage of a geographical area can be changed dynamically SON can be used to get information for providing the necessary configuration Resources are aggregated and dynamically allocated Reconfigurable BSs and controllers to support multiple Radio Access technologies 16
  • 17. Mobile and Cloud Infrastructure Convergence RRHs SDN Network Controller Centralized BBU Pools Core Network entity Network Devices in SDN Terminology 17
  • 18. Aricent eNB IPR Readiness for C-RAN Solution ENodeB Framework RAN on the Cloud will need to cater to variable capacity requirements and host multiple cells. Aricent Layer 3 and Layer 2 including Scheduler, MAC, RLC, PDCP, GTPU, are scalable for multicore architectures, supports multiple form-factors (femto, pico,micro) and different capacity requirements based on deployment. Single instance of Aricent Layer 3 can handle multiple cells/sectors hosted on Cloud RAN equipment and can interface with cells/sectors hosted on other Cloud RAN equipment on X2 link. OAM & SON Client RRM RRC,S1-AP,X2-AP Schedul er PDCP, RLC,MA C GTPU Aricent Layer 2 can handle one cell/sector per instance and multiple instances of Layer 2 can be utilized to handle multiple cells/sectors. 18
  • 19. Cloud Ready Aricent EPC Framework Router eNodeBs Top of Rack Switch Top of Rack Switch MMEs HSS SGWs PCRFs Subnet 1 Subnet 2 Integrated software offerings for MME, Serving GW, PDN GW, HSS and PCRF nodes for OEMs developing cloud EPC solutions running in clusters across virtualized hardware with separated routing tables PGWs ISP 2 EPC Frameworks Cloud Enablers Multi-tenant solution Scalable deployments EPC on virtualized environment 19
  • 20. Summary The promise of SDN and C-RAN: Mobile and Cloud Infrastructure Convergence Significant improvements in the manageability and flexibility of the network Prevent the networks from becoming prohibitively expensive to deploy Easy scalability Helps in the addition of new services without the need to add more hardware Easier for operators to exploit revenue opportunities Meet time-to-market challenges Helps reduce CAPEX and OPEX needs Ability to tailor the network "on demand" to customer needs Automated traffic management Improved bandwidth engineering SDN and C-RAN are the helping hands that will help LTE realize its true potential 20
  • 21. Confidentiality Statement Confidentiality This material contains information that is confidential and proprietary to Aricent. Recipient may not distribute, copy, print or repeat information in the document Legal Statement This presentation sets forth Aricents current thought and is subject to change at any time without notice. Aricent is not liable for any direct or intended commitments as may be inferred from the ensuing presentation. All information shared in this document is covered under a mutually signed NonDisclosure Agreement. Proprietary & Confidential. Aricent Group 2013 21