Comparing Home Networking Technologies Comparing Wireless Networking Technologies for the Broadband Internet Home Dr. Kevin J. Negus Chief Technical Officer Proxim, Inc. November 27, 2001

Comparing Home Networking Technologies Some Useful Acronyms Bluetooth –The Special Interest Group or the Technical Spec HomeRF –The Working Group or the Technical Spec IEEE – Family of WLAN “standards” – “MAC” – original MAC layer based upon –802.11FH – now obsolete freq hopping PHY layer –802.11DS – original 1997 direct sequence PHY (1,2 Mb/s) –802.11a – ratified 5 GHz OFDM PHY layer (up to 54 Mb/s) –802.11b – ratified high rate direct sequence PHY layer (5.5,11 Mb/s) –802.11e – MAC enhancement for QoS under development –802.11f – AP-AP communication –802.11g – higher rate “direct sequence” PHY layer –802.11h – DFS/TPC enhancements for 5 GHz operation –802.11i – MAC security improvement under development

Comparing Home Networking Technologies Agenda Broadband Internet Home Candidate Wireless Home Networking Technologies Introduction to HomeRF Technology Comparison of Candidate Technologies Summary

Comparing Home Networking Technologies US Broadband Internet Households

Comparing Home Networking Technologies Desired Services US Consumers want from a “Telecom Bundle” High-speed data is not enough – MUST support toll-quality voice and streaming media services.

Comparing Home Networking Technologies Candidate Wireless Home Networking Technologies IEEE b (or “WiFi”) –Wireless “equivalent” of Ethernet HomeRF –Wireless Ethernet plus multi-line toll-quality cordless voice and multiple streaming media sessions –Addresses the major interference and security problems consumers have with b at home Bluetooth –Much lower power draw for ad hoc connectivity –Not a candidate for “backbone” home network –But, consumers will still want to operate Bluetooth devices in their homes – so operation in presence of multiple Bluetooth devices is important

Comparing Home Networking Technologies HomeRF 2.0 Capabilities Summary 10 Mb/s peak data rate with fallback modes of 5 Mb/s, 1.6 Mb/s and 0.8 Mb/s Powerful and effective security measures against eavesdropping, service denial and unauthorized access Up to 8 simultaneous prioritized streaming media sessions for audio and video Up to 8 simultaneous toll-quality two-way cordless voice connections (based on DECT) Active interference avoidance and mitigation techniques

Comparing Home Networking Technologies HomeRF Capabilities Roadmap Enhanced Enhanced Video Video Voice/Audio Voice/Audio Basic Video Basic VideoData ‘2000 ‘2001 ‘2002 ‘2000 ‘2001 ‘ Mbps 10 Mbps 20+ Mbps Gateways Gateways Music Devices Music Devices Web Tablets Web Tablets Cordless Phones Cordless Phones Video Tablets Video Tablets Set Top Boxes Set Top Boxes Internet

Comparing Home Networking Technologies HomeRF Network Topology Broadband Internet Control Point (CP Class 1) Laptop (A-node) Internet Appliance (SA-node) Audio Player (S-node) Cordless Handset (I-node) Wired network

Comparing Home Networking Technologies Existing Upper Layers TCP UDP IP DECT HomeRF MAC Layer HomeRF PHY Layer “Ethernet” Data Path Streaming Media Path Toll-Quality Voice Path CSMA/CA Priority CSMA TDMA Network Layer View of HomeRF

Comparing Home Networking Technologies HomeRF – MAC Layer Basics time Data Networking Bulk of time is allocated to data networking 1 2 Priority Streams Within data networking time, streaming media sessions get priority access Voice Calls Reserved time period based on number of active voice calls Hop Re-Transmit If voice packets fail, they can be re-transmitted at the start of the next frequency

Comparing Home Networking Technologies HomeRF/Bluetooth PHY Layer Basics and Commonality Band and Channel Access –2.4 GHz, frequency hopping Modulation and Transmitter –FSK, direct conversion, constant envelope –Nominally 100 mW saturated output power Transceiver Architecture –~ 200 us turnaround using standard synthesizers on a single VCO Single-chip PHY CMOS RFIC –Practical today for either HomeRF or Bluetooth or dual-mode for both

Comparing Home Networking Technologies Key Comparison Attributes Voice Support –Consumer voice revenues are >10X data revenues –Cordless phones outsell wireless data devices >50X Streaming Media Support –Internet audio and video are key apps for broadband Interference Immunity and Scalability –Bluetooth, cordless phones, microwave ovens –High density housing with many adjacent networks Security –PHY/MAC attributes are critical since end-end solutions are generally not available in the home

Comparing Home Networking Technologies Voice Support IEEE802.11b has no explicit voice support –No prioritization for voice, no bounded latency mechanism for voice, no standard software stacks for voice features HomeRF was designed to support high quality, multi-line cordless telephony –Up to 8 simultaneous voice connections –10 ms bounded latency –Frequency diversity and hopset adaptation provides high quality even with severe interference –Maps directly into DECT for full CLASS features –A ratified global standard for multi-line cordless telephony (and much more)

Comparing Home Networking Technologies Streaming Media Support IEEE802.11b has no explicit streaming media support –Demos work fine, but network loading can wreak havoc on VoIP phones or streaming videos –Interference and scalability issues not withstanding, e should eventually address this issue HomeRF was designed to support multiple prioritized streaming media sessions –Up to 8 consecutively prioritized levels –One-way (audio/video) or two-way (VoIP/videophone) –Frequency diversity and flexible re-try buffer length provides high quality even with severe interference

Comparing Home Networking Technologies Interference Immunity and Scalability b has only 3 wide, static channels –Channel bandwidth ~ 17 MHz, fixed location –Only interference avoidance mechanism is time diversity (wait for the interferer to leave) –Fast hopper like Bluetooth is devastating –DS cordless phones can shut entire network down –Always shares the bandwidth with foreign networks HomeRF has narrower, dynamic channels –Channel bandwidth ~ 1.0/3.5 MHz (low/high rate) –Employs frequency and time diversity as well as hopset adaptation with static interferers –Ignores foreign networks for graceful degradation in high network density environments

Comparing Home Networking Technologies Security b has 3 well publicized security flaws –Weak encryption with poor 24 bit IV management –“Open” network access –Trivial mass denial of service susceptibility HomeRF addresses all 3 concerns –128 bit encryption standard with tamper-resistant 32 bit initialization vector –No equivalent of the “open” access mode and spec-compliant devices cannot pass promiscuous packets above the MAC –Mass denial of service virtually impossible due to frequency hopping PHY and ignoring foreign NWIDs

Comparing Home Networking Technologies Other Comparison Attributes Cost –HomeRF starts from a cordless telephone cost basis –BUT the market sets the price!! Range –HomeRF and b are roughly similar Peak Data Throughput –HomeRF and b are roughly similar Power Consumption –HomeRF power-savings devices have < 10 mW standby with full TCP/IP connectivity Network Topology –HomeRF uniquely supports host/client and peer- peer simultaneously

Comparing Home Networking Technologies What about IEEE802.11a or HiperLAN2 for the home? Much higher peak data rates More Bandwidth, “Cleaner” Bandwidth MAC layer Considerations –802.11a same as b for MAC Lacks explicit voice and streaming media support Relies on upper layers for strong security solution –HiperLAN2 has excellent QoS capable of supporting voice and streaming media But as yet, no cordless telephony infrastructure with range, power and features comparable to DECT or HomeRF Limited silicon availability at low cost Conclusion – Ideal solution for the enterprise –Far greater system capacity than b

Comparing Home Networking Technologies What about DECT “plus Data” for the home? DECT is the world’s most successful multi-user cordless phone standard DECT performance sets the expectation for any competitive voice networking technology DECT can support credible data extensions –~3 Mb/s performance demonstrated –Probably sufficient for many home applications –BUT, as currently specified DECT “plus Data” has: Limited interference mitigation for global 2.4 GHz band operation No available silicon Unclear roadmap to competitive higher data rates Conclusion – HomeRF = DECT “plus Data”

Comparing Home Networking Technologies Market Positioning Business Market [802.11a/HL2 centric] Wireless Ethernet Wireless Ethernet Performance Performance Roaming Roaming Home Market [HomeRF centric] Low Cost, Secure Low Cost, Secure Toll-Quality Voice Toll-Quality Voice Streaming Media Streaming Media Mobile Market [Bluetooth centric] Ad Hoc Connectivity Ad Hoc Connectivity Low Power Low Power Low Cost Low Cost

Comparing Home Networking Technologies Summary HomeRF combines 10 Mb/s data, toll- quality voice and streaming media for the Broadband Internet home HomeRF is uniquely optimized for the Broadband Internet home More information at