ACM SIGCOMM computer communication review

• DOI: 10.1145/1037107.1037111
• Publication Date: 2005-01-26T16:49:14Z
• Authors: Andrew T. Campbell; Mischa Schwartz
• Keywords: Mobile broadband

At some point in the future, how far out we do not exactly know, wireless access to Internet will outstrip all other forms of bringing freedom mobility way web, communicate with each other, and conduct business. In short, is going mobile wireless, perhaps quite soon. A number diverse technologies are leading charge, including, 3G cellular networks based on CDMA technology, a wide variety what deemed 2.5G (e.g., EDGE, GPRS HDR), IEEE 802.11 local area (WLANs). Wireless ISPs offer these users. case, handsets come software radios that simultaneously support multiple on-the-fly; for example, high-bandwidth urban areas rural areas. Each technology has its pros cons. First second generation systems low bandwidth voice services analog digital respectively. The designed carry voice, video data simultaneously, rates 144 Kbps fast-moving users vehicles, 384 slower moving pedestrian users, 2 Mbps from fixed locations. Note within cell share rates. higher capacity increased spectral efficiency but retain circuit-switched, hierarchical architecture. contrast, WLAN offers even considered IP friendly because it link layer very similar wired Ethernet. However, comparison networks, only operates area, supports best effort services, uses shared unlicensed spectrum where few quality assurances can be provided Recently, there been considerable amount press slow rollout 3G. signs optimism. Japan's NTT DoCoMo started offering October 2001 Tokyo area. This came after initial postponement by providers Japan Europe. Since May 2001, 5,000 residents have using new phones improved i-mode service real-time videoconferencing. 64 circuit carries audio combined. One guest editors had opportunity use trial handset set up call colleague taxi while traveling through Tokyo. call, which used MPEG4 presented mixed experience setting between two taxis was exciting. I-mode currently 29 million subscribers hopes keep figure rising offerings. radio network WCDMA core ATM switching. Many carriers US Europe keenly watching happening United States eager follow suit rolling phases emphasis such as GPRS, provides an always-on connection allows toggle surfing phone or text messaging without losing connection. Carriers Europe, invested more than $100 billion buy licenses need invest another build-out keeping close watch DoCoMo's successes failures. vast majority deployed today 802.11b operating at 2.4 Ghz 11 Mbps. companies demonstrated a, 5Ghz band 54 fact, Atheros Communications "turbo-networking" mode delivers 108 Mbps, roughly equivalent Fast cost so prohibitive many operators pushed brink bankruptcy. As result, small sharing infrastructure. infrastructure frequency bands cheap equipment. Cheap, base-station transceivers priced less $1,000, transceiver cards around built into computers. Public LANs handle large volumes significantly lower costs compared technologies. benefit differential offered makes disruptive migrate 2G Disruptive characterized being cheaper performance sustainin g solutions). Most public enterprise WLAN, secure, robust spectrally efficient, simply cheap, high bandwidth, easy build configure, and, importantly, works. Typically, customers initially satisfied when they first introduced. For compete marketplace solutions, would capable building metropolitan suitable voice-over-IP enabling communications. Sharing means cannot managed tightly controlled, isolation operators, assuring performance. Historically, however, tended resolve problems mature begin capture market share. Examples extensions us today. Here New York City companies, university campuses, coffee shops stores web technology. Columbia University, students faculty move campus. Companies MobiStar Waypoint provide connections hotels, airports cafes. Around Manhattan, Starbucks Internet. grassroots level, community groups putting antennas cities free Some predict "freenets", feel reminiscent Napster, ultimately succumb sustained corporate challenge across dense road success fledgling may littered business, regulatory obstacles. There standards bodies, industrial fora vying define future end result faced confusing array choices next networks. seamless mobility, paging, complex costly connection-oriented networking lacks inherent flexibility, scalability, effectiveness found Mobile represents simple scalable global solution fast handoff control, location tracking, authentication distributed policy management also interest emerging personal ad hoc sensor How interwork active research. micro-mobility protocols Cellular IP, Hawaii, Hierarchical IP) schemes discussed IETF Working Group address scalability issues. These environments hosts change their attachment frequently basic protocol tunneling mechanism introduces overhead terms delay, packet loss signaling. applications voice-over-IP) noticeable degradation frequent handoff. Establishment tunnels introduce additional delays process, causing delayed delivery applications. delay round-trip incurred registration request sent home agent response back foreign agent. Micromobility aim movement domain) interaction enabled reducing during eliminating possibly distant agents remain inside coverage Eliminating this manner reduces signaling load experienced mobility. numbers grow associated management. paging techniques minimize optimize Currently, paging. An important characteristic ability reduce related migrations taking account host's operational (i.e., idle). When becomes norm then efficient tracking idle Support "passive connectivity" balances design considerations. approximate information requires thus over air interface network. Reducing interfaces preserving power reserves hosts. Seamoby tasked developing protocol. papers special issue issues challenges above. We received total 32 excellent submissions -- much greater our expected. different regions world addressed aspects paper reviewed three experts, who evaluated technical content suitability publication issue. difficult job selecting six those submitted. Several deserving could accommodated space. hope see appear later ACM SIGCOMM Computer Communication Review. enhancements better context transfer, telephony, final deal paper, Jonathan Lennox, Kazutaka Murakami, Mehmet Karaul Thomas F. La Porta, Lucent Technologies, discuss internetworking telephony telecommunications authors propose directly interconnect UMTS SIP systems. Rajeev Koodli Charles E. Perkins, Nokia, deals relocation Context transfer refers state QOS state) particular VoIP) needs re-established show uninterrupted services. Pars Mutaf Claude Castelluccia, INRIA, proposes adaptive per-host observe existing proposals literature promote static manually configured argue dynamic takes host traffic patterns Robin Kravets, Casey Carter Luiz Magalhaes, University Illinois, Urbana-Champaign, cooperative approaches user necessary functionality devices collectively comprise network) interact seamlessly integrated Jyoti Raju J. Garcia-Luna-Aceves UC Santa Cruz, present routing called source tracing compare (DSR). Both on-demand table-driven implementations considered. issue, Samir Goel Tomasz Imielinski, Rutgers considers problem monitoring prediction-based scheme visualized leveraging concepts image processing. before goes truly mobile. impact TCP performance, security over-the-air, further study toward Finally, wake recent attack City, anticipate advances rapidly deployable infrastructure, self-configuring - forming disaster relief great pleasure put together like thank contributions reviewers time, energy, comments helped shape you enjoy do.