The Wireless Future Ed Knightly ECE/CS Departments Rice University - Killer apps - The wireless device - The big challenges

Ed Knightly The WiFi Laptop: A Killer App? (or 3G Laptop, or Metricom Laptop) Why do we (academics/researchers) love it? –Location freedom –Time efficiency However, we’re atypical What is it? – Portable office with high- speed Internet access

Ed Knightly The WiFi Laptop: A Niche App Economics –Value added? Re-locate office. Not exciting to masses. –$30/month extra for same thing (except slower, less secure, …) Device –Most people don’t/won’t carry laptops everywhere (even at 2 lbs) Niche demand –Few have freedom of location to work –Few require constant high bandwidth connectivity to work Preliminary data –Tmobile – 10,000 WiFi subscribers –Metricom – 50,000 subscribers at peak –Total industry revenue 2002: $6M (source: Insight On Wireless)

Ed Knightly Meta-Properties of Killer App’s Run on a PDA or cell phone –Pocket-sized devices only Enabled or enhanced by PDA + wireless + mobility (vs. worse-than-wired)

Ed Knightly Enabled & Potential Killer App’s (1/2) Exploit location specific information –Find the nearest {café, movie theater, …} –Wireless dating match-maker game –Spy game

Ed Knightly Enabled & Potential Killer App’s (2/2) Immediacy/timeliness of information is critical

Ed Knightly Implication 1: Seamless Multi-tier Seamless WiFi/3G integration is critical 3G cellular for coverage WiFi for efficient delivery of high aggregate bandwidth 3G WiFi –PDA’s have modest bandwidth requirements due to form factor –High bandwidth requirements in aggregate –0.4 vs. 38 Eurocents-per-Mb for WiFi vs. 3G (source Analysys)

Ed Knightly Implication 2: Low Power Trumps High Bandwidth Power efficiency increasingly critical –Minimum power to achieve moderate throughput –Minimizing power/bit is well understood at PHY layer –Open problem: power aware MACs, OS, and applications Gb/sec

Ed Knightly Implication 3: Radio Routers Real hot-spot cost is backhaul and management –$10k / hot spot + T1 for Mobilestar –Breakeven customers-per-AP too high Radio routers –Directed point-to-point radio links (vs. T1’s) –Challenge: scalable efficient infrastructure based on WiFi

Ed Knightly Implication 4: Multi-Carrier Crunch Today: one carrier per hot spot (T-Mobile, Wayport, …) –Success will lure more carriers Problem: WiFi is worse than a zero-sum-game –Multiple APs will clobber each other Unlikely solution: Roaming (what is added value of 2 nd carrier) Promising solution: Virtual Access Point –One physical infrastructure, virtualize MAC and services –Commercial solutions exist for wired routers –Open problem in wireless

Ed Knightly Implication 5: A New IEEE Industry and Mobicom: MAC Balkanization –MAC for multi-rate –MAC for directional antennas –MAC for low power –MAC for QoS –MAC for fairness Challenge: All-in-one WiFi responsive to user needs –Ex. Directional antennas and QoS for low-power WiFi VoIP

Ed Knightly And the Wireless Future Is… Device: Turbo-charged multi-tier wireless PDA –Always and instantly available –44k/128k/WiFi automatic and transparent –WiFi is a hot-spot turbo boost for user, efficient infrastructure for carrier Applications: Enabled apps vs. worse-than-wired –Unique to wireless/mobile/PDA/low-bandwidth scenario Implications: Technical challenges abound –Low power, WiFi+3G integration, innovative apps –MAC, Virtual AP, …