The Fusion of IP and Wireless Jacob Jorgensen president, CTO and founder

The problem: Wireless broadband should be incredibly important, but it isn’t… … yet

Wireless should be an important broadband option  Broadband is exploding  Millions of additional subscribers want broadband services, but can’t be reached with DSL and cable modems  Wireless should be an answer:  it could reach many of these subscribers  it needs only one truck roll  it needs no cable conditioning  it can operate faster than cable modems and DSL  wireless operators aren’t dependent on the LEC  in some countries, wireless is the only economical choice

But today, wireless is only a very small part of the broadband market

Why?  Wireless is too expensive  Wireless is too slow  Wireless can’t get through the trees  Wireless is too hard to install  Wireless can’t guarantee bandwidth levels  Wireless can’t support QoS for voice, video, and data

What is the ideal solution?  A complete IP-aware wireless broadband system  Consistent with the emerging /.4 standard  Optimized for SME and residential  World-class RF technologies, including burst-mode OFDM, which deliver:  high RF throughput  non-line-of-sight operation  high subscriber penetration  A unique broadband access QoS architecture, which delivers:  bandwidth guarantees  guaranteed, bandwidth-efficient support for voice and video  high protocol throughput

What do operators need in a wireless broadband system?

meeting the operator’s needs RELIABILITY BANDWIDTH VOICE AND VIDEO INSTALLABILITY & MANAGEABILITYSLAs PER-SUBSCRIBER COST PROTOCOL PERFORMANCE COVERAGE Penetration to a high % of potential subscribers Maximize bandwidth, and at a minimum, more than DSL or cable A system that keeps subscriber data moving Equipment costs that meet the subscriber expectation for residential broadband Easy to install and manage; another key element of system cost Differentiated services that give users what they expect and increase operator profits Differentiated services that meet the needs of an increasingly sophisticated user base Every part of the Internet impacts every other part; subscribers only care about their experience PRIMARILY INTERNETWORKING PRIMARILY RF

OFDM: very resilient, non-line-of-sight  Single carrier uses one large carrier  Interference and multipath can block the entire signal  Errors often require retransmission  OFDM uses many small carriers  Interference and multipath affect only a small portion of the signal  Most errors can be completely recovered with forward error correction

Dynamic modulation and FEC: optimizing throughput and resiliency Subscriber further from base station with more obstacles: lower-order modulation, maximum forward error correction residential tower Subscriber close to base station with few obstacles: higher-order modulation, minimum forward error correction residential

Dynamic TDD: optimal, dynamic balance of upstream and downstream bandwidth Bandwidth adjusts dynamically, frame by frame, based on user demand Frame 1 Frame 2 Frame 3 Frame 4 Frame 5 Upstream DownstreamUpstream Downstream Upstream Downstream

Quality of Service

Problems of present broadband wireless systems  Limitation in number of subscribers  Limited services and features  Inability to support real-time multimedia  Inability to manage subscriber usage  Inability to enforce access policies  Inability to provide broadband and narrowband services simultaneously  Low revenue & profit/RF Hz/system/month All adversely affecting the service provider’s business model

What is a reasonable definition of QoS in a broadband wireless system?   No added jitter or latency for time sensitive data  No added errors for error sensitive data  Minimal added traffic shaping  Guaranteed Services  Differentiated Services  Best Efforts Services  Ability to isolate effects of traffic types from each other  Ultimate test is mixture of real-time multimedia traffic and best efforts FTP and UDP traffic

System-level approaches for wireless QoS:  MAC layer must have a design specifically optimized for TCP/IP and UDP data transport  TCP and UDP traffic must be segregated  Link layer must be IP aware  Media access methodology must be deterministic so that timing requirements of flows can be met  System resources must be allocated on basis of traffic types and priorities  Scheduling of IP data transport must be done in a manner consistent with timing requirements of data  Hierarchical link sharing must be utilized

WirelineWireless Bit error rateLowHigh Bandwidth scopeInfiniteFixed Typical topologyPoint-to-point Point-to- multipoint Jitter, due to point-to- multipoint topology LowHigh Why an IP-aware protocol architecture is essential for wireless broadband IP access Ideal Solution Adaptive ARQ, Adaptive FEC, Adaptive modulation Predictive bandwidth reservation Centralized protocol analysis and scheduler Fast packet multiplexing, intelligent packet scheduling

Intelligent packet scheduling guarantees QoS for voice and video … Service provider network MAC Non-optimally scheduled flows: jitter and latency are introduced FTP TELNET HTTP SMTP VoIP Wireless broadband system

Intelligent packet scheduling guarantees QoS for voice and video IP QoS-aware packet scheduler FTP TELNET HTTP SMTP VoIP 1341… Service provider network MAC Non-optimally scheduled flows: jitter and latency are introduced Wireless broadband system 25

IP flow analysis & centralized scheduling optimize bandwidth efficiency & enforce QoS IP Flow SchedulerSAR and FramerIP Flow Analyzer From SP network backbone Latency-sensitive UDP Latency-neutral Low-priority Example IP Flow Priorities: High-priority Initial HTTP screens FTP, SMTP, etc. Intermediate-priority CPE IP Flow SAR & Framer CPE IP Flow Manager CPE IP Flow Identifier Subscriber Applications CPE IP Flow SAR & Framer CPE IP Flow Manager CPE IP Flow Identifier Subscriber Applications CPE IP Flow SAR & Framer CPE IP Flow Manager CPE IP Flow Identifier Subscriber Applications CPE IP Flow SAR & Framer CPE IP Flow Manager CPE IP Flow Identifier Subscriber Applications CPE IP Flow SAR & Framer CPE IP Flow Manager CPE IP Flow Identifier Subscriber Applications CPE Base station MAC Frames over RF Media

IP flow analysis & centralized scheduling optimize bandwidth efficiency & enforce QoS To SP NETWORK BACKBONE CPE IP MAC SAR & Framer CPE IP Flow Identifier CPE IP Flow Manager Subscriber Applications CPE IP MAC SAR & Framer CPE IP Flow Identifier CPE IP Flow Manager Subscriber Applications CPE MAC SAR & Framer CPE IP Flow Identifier CPE IP Flow Manager Subscriber Applications CPE IP MAC SAR & Framer CPE IP Flow Identifier CPE IP Flow Manager Subscriber Applications CPE IP MAC SAR & Framer CPE IP Flow Identifier CPE IP Flow Manager Subscriber Applications Uplink IP Flow Reservation Scheduler Latency-sensitive UDP Latency-neutral Low-priority Example IP Flow Priorities High-priority Initial HTTP screens FTP, SMTP, etc. Intermediate-priority IP Flow SchedulerSAR and FramerIP Flow Analyzer CPE Base station CPE MAC Frames over RF Media

Predictive bandwidth reservation for voice and video N+1 N+2 N+3 N+4 N+5 N+6 N+x N Frame Sequence Number MAC Frame Scheduler Downlink SubFramesUplink SubFrames Voice, video advance reservations (Current frame = N) Increasing Slot Number Increasing Slot Number

Wireless throughput and QoS: overall impact of an IP-aware architecture y1y1 Increasing QoS yiyi Internet backbone Service provider network Wireless system y2y2 y7y7 y8y8 y3y3 y4y4 With IP-aware architecture Without IP-aware architecture Subscriber site y5y5 y6y6

Let’s summarize

Let’s summarize: what do operators need?  A signal that can reach a high percentage of subscribers  Very high data rates (up to 240 Mbps per base station)  A scalable, reliable system that’s easy to install and manage  A system that’s cost-effective enough to serve the consumer broadband market  The ability to sell -- and genuinely deliver -- SLAs  Great QoS support for voice, video, and data  Maximum operator revenues and profits, due to:  service level agreements  very high bandwidth efficiency  strongly differentiated capabilities