The Future of Software Radio: Wireless Network Cloud
Upcoming SlideShare
Loading in...5

The Future of Software Radio: Wireless Network Cloud






Total Views
Views on SlideShare
Embed Views



2 Embeds 4 3 1



Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.


11 of 1

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
Post Comment
Edit your comment

    The Future of Software Radio: Wireless Network Cloud The Future of Software Radio: Wireless Network Cloud Presentation Transcript

    • The Future of Software Radio: Wireless Network Cloud Parul Gupta , Smruti Sarangi, Shivkumar Kalyanaraman [IBM Research – India] Zhen Bo Zhu, Lin Chen, Yong Hua Lin, Ling Shao [IBM Research – China]
    • Outline
      • Cellular wireless systems and convergence trends (esp in emerging markets)
      • Today’s 2G/3G architectures and the trend towards 4G (all-IP and OFDMA for PHY/MAC layers)
      • Increasing computational costs, low utilization with future generations of technology, upgrade cycles, growing maintenance / OPEX costs.
      • SDR evolution:
        • Firmware OTA upgrades on vendor platforms,
        • From DSP/FPGA platforms to Hybrid IT platforms,
        • Multi-technology / multi-operator support
        • Virtualization & cloud given fiber-to-tower availability
    • Wireless: short technical summary Wireless IT convergence Wireless networks are designed to maximize spectral efficiency, support mobility, coverage, and Quality-of-Service under severe spectrum/bandwidth constraints In emerging markets the dependence on wireless is high and growing. ARPU pressures are severe: $2 incremental ARPU today. Operators aggressively outsource their (wireless/wired) networks and IT.
      • Scarce bandwidth
      • (10-100 MHz/operator)
      2. Spectral Efficiency: MHz -> Mbps (signal to noise ratio is key!) Rate Mobility 2G 3G 4G 802.11b WLAN 2G Cellular Other Tradeoffs: Rate vs. Coverage Rate vs. Delay Rate vs. Cost Rate vs. Energy 3. Tradeoffs: Rate vs X (no free lunch!) Today With femto cells & MIMO antennas
    • Wireless Convergence: Closed Vertically Integrated to Horizontal Open TDMA/CDMA Circuit Voice; Data overlay 2G/3G wireless Integrated MAC, network functions Radio layer: OFDMA/MIMO Network layer: IP Middleware: IMS, SDP Apps: Unified Comms (multimedia), Smarter Planet, mobile VAS, Internet apps, Spoken Web/SMS platforms… 4G wireless
      • System: IT and wireless systems are approaching similar system architectures
      • Network Services: Convergence of enterprise wireless and operator wireless services
      • Application/Solutions: Seamless integration and interaction of wireless infrastructure and mobile applications
      Convergence at Systems Level Convergence at Network Services Level Convergence at Application/Solutions Level There is another interesting twist in this wireless / IT convergence at the systems level
    • Radio network controller Radio network controller Mobile switch center Service support node Gateway PSTN Access Network Core Network 2G-3G wireless network architecture Service Network 4G Wireless Network over Wireless Network Cloud Internet BS cluster BS cluster Cloud of Wireless Access Network + Core Network BS BS BS BS SMS/MMS WAP GW SMS/MMS IMS Content Service Web Service Edge gateway Management Server Billing Edge gateway
    • Service support node PSTN Service Network 2G/3G/4G Wireless over Wireless Network Cloud Internet BS cluster BS cluster Cloud of Wireless Access Network + Core Network SMS/MMS IMS Content Service Web Service Edge gateway Management Server Billing Edge gateway Service on Edge
    • Mobile Infrastructure Network Hierarchy Core Network Radio Access Network Challenges : The radio access network is a costly and continuous investment ($100B+). With reducing ARPUs and need for broader nationwide coverage, there are more initiatives for sharing infrastructure
    • Various Forms of Infrastructure Sharing in Wireless Networks Network Sharing (eg: rural) Base Station Sharing (leads to cloud) Antenna Sharing Tower Sharing (very popular) BSC BTS Owner #1 Retail Owner #2 Retail MSC BSC BTS Owner #1 Network Owner #2 Network BSC BTS BSC BTS Owner #1 Network Owner #2 Network BSC BTS Base Band Unit BSC Owner #1 Network Owner #2 Network BSC SDR BTS RRU O
    • Towers: Passive vs Active Infrastructure Sharing
    • Passive Sharing and Tower Companies Eg: Indus Towers (JV controls towers of Bharti, Vodafone, Idea) has 100K towers. Tata Teleservices, Aircel have signed deals with BSNL for sharing 60K+ towers.
    • Towards Active Sharing: Unbundling Base Stations: RRU + BBU
      • Distributed base station
        • RRU (Remote Radio Unit)
        • BBU (Base Band Unit)
      • Two key standards enable distributed base station development
        • CPRI
        • OBSAI
      • Benefits of distributed base station
        • Reduce cost of facilitate infrastructure
        • Reduce power consumption
        • Easy of installation
        • Flexible deployment model
      Traditional Integrated Macro BS Distributed BS : RRU + BBU RRU BBU
    • Distributed base station deployment #1: under the tower
      • 70% - 80% power consumption is RRUs
        • 3 RRU: 100 – 150W/RRU
        • 1 BBU: 100W
      • Requirement & Challenges to BBU
        • light weight < 10Kg
        • small size (1U – 2U)
        • low power consumption (< 100W)
      Scenario #1: Unbundle at the tower BSC BBU MSC BBU RRU RRU <100m RRU-BBU Distance <100m 5-10Km 5-10Km
    • Software Radio & Software Defined Radio: One way of BBU impln
    • Multi-Technology Software Radio: 1 BBU Bladecenter vs 5 boxes
    • Multi- Operator Base Station with Software Radio
    • Active Infrastructure Sharing: Field Trial in India (IBM/partner)
    • Unbundled SDR BS w/ Open Wireless Interfaces & IT Platforms
    • Distributed base station #2: distributed RRU + centralized BBU pool
      • Benefits
        • Fit for super urban, urban with high density of traffic
        • Highly scalable
        • Improve utilization by resource sharing
        • Reduce management cost
      • Requirements & Challenges to BBU
        • High density
        • Resource sharing with BBU pool
        • Low power consumption
      • Key barriers:
        • Fiber distance (<10Km)
        • Increasing IO data throughput >10Gbs with LTE
        • Fiber construction cost
        • Synchronization in long distance network
      • Case in China:
      • World largest TD-SCDMA BBU pool
      • Max support 72 RRUs
      • Power: 400W
      A city like Bangalore or Delhi could be served from <10-15 pooled sites. Scenario #2: central deployment BSC BBU Pool RRU BBU BBU BBU BBU MSC 10KM RRU
    • Wireless Network Cloud: Convergence of IT Platforms, SDR & RRH, Cloud Computing Principles & Fiber-to-the-tower
      • End-to-End IP Infrastructure in 4G
      IT & Cloud Computing Techniques Software Radio Technology/ Hybrid IT Systems Remote Radio Header Technology Wireless Network Cloud BaseStation Pool Antenna + Remote Radio Header Fiber (> 10Km)
      • Multiple points collaborate to mitigate ICI
      • or align interference for cancellation.
      Multi-cell environment with frequency reuse factor 1 Optical fiber Optical fiber Optical fiber interference Wireless Network Cloud Potential: Distributed Interference Management. Eg: Collaborative MIMO for Elastic Capacity Allocation
    • An e2e Demo has been setup in IBM CRL/IRL (WiMAX@2.4GHz) Collaboration of IBM China and India Labs: Multiple base-stations on common IT platform, USRP & e2e flows
    • BS SDR System Architecture MAC: Software Components MAC and adapter Stacks Control & management Switch of BS system BS edge router MAC instance MAC instance MAC instance Adapter Adapter Adapter Fast path data processing Slow path message processing Scheduling Fragment & packing Packets Encryption Concatenation Packet Extract Defragment & unpacking Packets Decryption MAC Management Downlink Uplink DL Adapter UL Adapter Msg. Msg. Msg. Key technical challenges being addressed (IRL+CRL)
      • How to map the wireless software radio (SWR) stack/workload to massive multicore and hybrid architectures?
      • How to meet QoS and real-time requirements for the VoIP application, especially since the wireless software stack (such as PHY and MAC layer) will be implemented in software using a regular OS?
    • Laundry List of Challenges
      • Difference from regular computational, storage cloud: “ real-time computational cloud ”
        • Focus on very high performance, real-time synchronized behavior.
        • Cooperative techniques require greater degree of rigor in performance management
        • Wireless = Critical infrastructure. Availability / reliability equally important as real-time performance support.
      • Choice of underlying platforms : hybrid systems, commodity servers and mapping it to VMs (eg: MAC VM may work well on system A, and PHY VM work well on system B).
        • Need real-time virtual switches that can tie together such component VMs into a pipeline (Network -> MAC -> PHY)
        • Cooperative techniques require redesign of protocols / implementation
      • Multi-tenancy, elastic provisioning of real-time resources, tracking performance / availability risks (eg: 4-5 nines)
        • Providing backup for virtual base-stations from multiple data center sites: “cloud” attribute.
      • Helping the industry move from an integrated “box” model to a software + outsourced services model.
        • Hypothesis: ARPU pressures faced by providers will ultimately drive such a move. Aggressive outsourcing happening in markets like India.
    • Summary
      • Software radio is an emerging technology.
      • The long term potential of software radio involves:
        • Unbundling base stations into hardware, software, RF components.
        • Application of IT platforms , open wireless interfaces to SDR; opening up a open-source community of developers
        • Allowing flexibility for BS software to be virtualized , and consolidated into pools for reduced CAPEX/OPEX, higher utilization and change business models
        • Fiber to towers will allow pooling and application of the Cloud model.
      • Wireless network cloud can provide new benefits.
        • Elastic capacity allocation & higher utilization/lower costs
        • Distributed Interference Management: Collaborative MIMO etc (5 th Generation Wireless)
        • Integration of edge-based services at the cloud site. Eg: caching, content delivery, unified communications, enterprise app delivery, cloud-based application delivery etc
      • Perfect storm of “cloud” challenges:
        • Real-time, synchrony/performance-critical, ultra-high reliability requirements.
    • Terminology
      • RAN – Radio Access Network
      • CN – Core Network
      • BTS – Base Station = BBU + RRU
      • BSC – Base Station Controller
      • BBU – Base Band Unit
      • RRU – Remote Radio Unit
      • RNC – Radio Network Controller, BSC in 3G
      • NodeB – BTS in 3G
      • eNB – Base Station Node in LTE
      • LTE – Long Term Evolution (E-UTRAN)
      • AIPN – All IP Network
      • NEP – Network Equipment Provider