IEEE Computer Society Technical Committee on Computer Communications

(TCCC)

 

     November 2005

 

Welcome from the Chair – Joe Bumblis

 

Welcome to the November, 2005 TCCC newsletter. There are several exciting events to share with you - the TCCC membership. First, it is time to elect a new TCCC Chair.  Although it has been my pleasure to serve as TCCC Chair these past four years, by TCCC Charter a new Chair must now be elected. The Call for Nominations has been posted on the TCCC web page (http://tab.computer.org/tccc).  I urge all of you to consider submitting your, or a colleagues, name for the position of TCCC Chair.  Please download the nominations form from the web page, fill in the name or names of folks you feel would make a qualified TCCC Chair, and E-mail to Stacy Wagner (s.wagner@computer.org) at the Computer Society by November 16, 2005. I offer a few final thoughts regarding the TCCC prior to the WoWMoM 2005 report.

 

Second, Archan Misra of IBM T. J. Watson Research Center and TCCC ExCom Member submitted a conference report detailing the WoWMoM 2005 conference held at the Russot Ramada Hotel in Giardini-Naxos, Sicily.

 

Third, there is one remaining conference in 2005 sponsored by the TCCC; LCN 2005 (http://www.ieeelcn.org). This conference and associated dates are included below.

 

I invite all of you to visit the TCCC web page and review the information currently available. An HTML version of this newsletter is now available on the TCCC web page (http://tab.computer.org/tccc).

 

 

A Few Thoughts Regarding the TCCC

By: Joe Bumblis, Chair, TCCC

 

On January 1, 2002 I was elected Chair of the TCCC.  I was the first Chair since 1985 when the TCCC became an inactive TC.  Since I became Chair, many new and exciting things have happened to the TCCC.  An Executive Committee (ExCom) was formed that exemplifies a ‘first’ even with regard to the pre-1985 TCCC organization.  I made every attempt to recruit folks from industry and academia that represent the ‘best’ in the area of computer communications and networking. A web page was developed to increase the communications between the TCCC membership and the ExCom.  Several new conferences were added since January 1, 2002 bringing the total number of conferences supported (in full or in part) by TCCC to nine. In addition to these nine conferences, we established a Cooperative Relationship with the CNSR conference (http://www.cnsr.info/Events/CNSR2005/) for two years allowing many opportunities for TCCC membership. With a continued commitment from the ExCom, we began quarterly Newsletters to TCCC membership containing TCCC news and events, new services, conference information, conference reports, and special technology reports offered by ExCom members or their colleagues. And finally, we grew the TCCC membership to almost 5,000 members making TCCC the third largest TC in the IEEE Computer Society. The establishment of a locally-administered TCCC database in conjunction with the Computer Society Unified Database Project TEchnical Committees Achieves (TECA - https://eckert.computer.org/tchelp/spcl145.htm) has enabled the ExCom to maintain a continued relationship with TCCC members.

 

Even with all of these accomplishments, there remains much to be done.  For example:

 

Online Publishing: Over the past several yeas, the TCCC ExCom conference calls always included preliminary planning of TCCC Web page online publishing to add value to the TCCC membership. This may include selected papers from TCCC sponsored conferences, invited papers for on-line publishing, and/or adding a TCCC web page link to conference paper submissions (for example: http://www.ieeelcn.org/lcn29papers.html ) as well as upcoming conference dates. This could also be accomplished through DS Online (ISSN: 1541-4922). See: http://dsonline.computer.org/ for details.  I would like the next Chair to continue this effort.

 

ExCom Chair Position: Several open Chair positions remaining on the TCCC ExCom. These include:

·        Permanent Finance Chair

·        Tethered Network Technology Chair

·        Protocol Technology Chair

·        Application Domain Technology Chair

These positions remain empty and should be filled to allow the TCCC to become more of a “Think Tank” environment capturing the expertise of the ExCom and TCCC members.

 

Contributions to Computer Society Journals: Many TC's offer publications to Computer Society journals.  The TCCC should strive to offer articles, research reports, or papers to such journals as IEEE Transactions on Networks, IEEE Internet Computing, and IEEE Transactions on Dependable and Secure Computing.

 

Webcasting and Online Conferences/Workshops: Final, I believe the TCCC should continue its focus on possible alternatives to TCCC members attending conferences and workshops. In past ExCom meetings, we discussed things like Webcasting, Chat Rooms, and video streaming of pre-recorded presentations. The IEEE supports a Webcasting service that should be investigated (http://www.ewh.ieee.org/soc/cpmt/press/keepup.html).

 

I would like to thank the ExCom membership (http://tab.computer.org/tccc/TCCCmembers.html) for their dedication and commitment to the TCCC.  I would also like to thank you – the TCCC membership - for your patience during the rebuilding of the TCCC, and your continued involvement in TCCC and Computer Society activities.  I wish all of you the very best in your careers and personal lives.  As always, please feel free to contact me (j.bumblis@ieee.org) at any time regarding the TCCC, the Computer Society, or to simply chat.

 

Thank you,

 

Joe Bumblis

 

 

IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WOWMOM 2005) Conference Report

By: Archan Misra

 

The sixth IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WOWMOM 2005) was held at the Russot Ramada Hotel in the lovely resort town of Giardini-Naxos in Sicily. From the 180 papers submitted, from 31 countries, the technical program committee selected a total of 57 full papers for oral presentation and 20 additional submissions for poster presentation. In addition, the conference comprised two workshops, two keynote speeches and one panel discussion. Around 120 participants from all over the globe attended WOWMOM 2005.

 

One of the highlights of the conference was the keynote speeches, provided a review of research advances and challenges in sensor networks and wireless network management. Prof. Adam Woliscz from the Technical University of Berlin delivered a keynote talk titled “Sensor Networks: A Hype or Real Challenge?” He first listed out the major advances in radio and processor technology, including reduced (~1MW) radio power consumption, that are likely to make one-dollar sensor devices a reality within the next 5-10 years. However, he highlighted how significant research is still needed to allow sensor devices to be addressed and queried using data-centric or descriptive mechanisms. One major challenge of such abstractions was that, while such abstractions made rapid application development easier, higher-level abstractions tended to be less energy-efficient.  Dr. Sudhir Dixit from Nokia Network Research Center delivered the other keynote titled “Designing Self Organized Wireless Networks—Is it Possible?” He started out by explaining how the gradual adoption of IPv6 and the extension of the Internet to include home appliances, sensors etc., were likely to change the topological properties of the Internet. He described how “small-world” and “scale-free” models describe the topological properties of the conventional wired Internet, and then explained the challenges of applying such models for wireless ad-hoc networks due to the typical physical limits on the size of a wireless link. Through an example of a relay-based access network, he then explained how how scale-free principles could be used to derived both the topological properties and routing mechanisms in wireless networks as well.

 

The main conference also featured an exciting panel on “The Future Wireless Networks: Managed vs. Decentralized?”, moderated by Milind Buddhikot from Lucent Bell Labs, and featuring 4 eminent panelists. Sunghyun Choi from Seoul National University mentioned that wide-area “3G” service itself was unlikely to be replaced solely by WLAN-based access, especially as fixed physical-layer wireless relays were being increasingly used by cellular providers to extend coverage to more difficult environments, such as large buildings and subways. Adam Woliscz opined that cellular networks were likely to evolve to a hybrid architecture, whereby nodes with poor connectivity to the base station would hop across other available cellular nodes using a secondary local area interface, thereby improving the use of the wide-area spectrum. Giuseppe Bianchi of the University of Rome “Tor Vergata” discussed his belief that the infrastructure cellular provider would survive, but would instead be complemented by additional “managed” WLAN networks that would use emerging techniques such as multiple antennas (for spatial diversity) to further improve the available WLAN bandwidth to 1Gbps and beyond. Igor Curcio from Nokia described his opinion that the real challenge to a WLAN/mesh-based architecture wasn’t the networks themselves, but the additional development cost associated with making 3G-based applications compatible to this mixed environment. In addition, audience members raised the point that the charging models for a mixed WWAN/WLAN environment needed to be developed before providers embraced such a hybrid architecture.

 

WOWMOM 2005  comprised fourteen regular sessions, covering a wide variety of topics including 802.11 MAC enhancements, energy-efficient computing in ad-hoc and sensor environments, application-layer adaptation and service composition for wireless multimedia services, and performance evaluation of both WLAN and mesh network testbeds. Some highlights include: Nicholas Bauer, et al from the Colorado School of Mines described a new approach for maintaining and exchanging global information in an ad-hoc network using a circulating “legend” packet that makes a random walk through the network; Ilenia Tinnirello, et al presented two papers on new methods of congestion window control and RTS/CTS signaling for fairness and better utilization in multi-rate 802.11-based WLANs; Paolo Bellavista, et al from the University of Bologna described their REDMAN middleware for efficient replication of read-only objects among central nodes in an ad-hoc network; Samir Das et al from SUNY Stonybrook described a new anycast extension of 802.11 that enables the link layer to forward packets along potentially many multiple routes; thereby increasing the probability of successful delivery; Milind Buddhikot et al from Bell Labs presented a position paper arguing for DIMSUMNet, an architecture for market-driven spectrum utilization (especially important since studies have demonstrated that over 60% of spectrum often goes unutilized in practice!!) that employs a regional-broker approach and defines a new band where spectrum is leased only for relatively short durations. Overall, two main themes of research seemed to be dominant (and perhaps reflect the current research focus of the academic and industrial research communities): a) new architectures and channel allocation policies for multi-radio mesh networks, and b) service and transport-layer adaptation techniques for supporting multimedia applications in wireless networks.

 

WOWMOM 2005 also organized two very interesting, well-attended and focused 1-day workshops.  The Autonomic Communications and Computing Workshop (ACC) presented research ideas on how networks could become self-managing, thus reducing their maintenance complexity. ACC received 33 submissions from all five continents, and the program included 12 papers and an  exciting panel (details available at  http://www.autonomic-communication.org/acc/program/ACC05-panel-report-final.pdf.) The Workshop on Trust, Security and Privacy for Ubiquitous Computing (TSPUC) addressed issues related to privacy management and trusted computing in decentralized, emerging environments, such as ad-hoc and sensor networks. The workshop program included 10 papers (selected from 48 submissions), a keynote speech and a panel.  The topics addressed during the workshop covered a wide range of topics from privacy policy to group key agreement in peer-to-peer networks and hybrid key establishment in sensor networks.

 

Next year, the 7th IEEE on a World of Wireless, Mobile and Multimedia Networks (WOWMOM 2005) will be held in Niagara Falls/Buffalo, New York, USA on June 26-29, 2006. Be sure to attend WOWMOM 2006 as it continues to provide a high-profile forum for researchers and engineers on exciting advances in the area of pervasive and wireless multimedia!!

 

Upcoming Conferences/Workshops Sponsored by the TCCC

 

The IEEE Conference on Local Computer Networks (LCN) — 30th Anniversary —

November 15-17, 2005

Sydney, Australia

Call for Papers (http://www.ieeelcn.org)

[100% sponsorship by TCCC]

 

For the past 30 years, the IEEE LCN conference has been the premier conference on the leading edge of practical computer networking. LCN is a highly interactive conference that enables an effective interchange of results and ideas among researchers, users, and product developers. Over the years, LCN has tracked many developments from the local network to the global Internet and the World Wide Web. In 2005, we are targeting embedded networks, wireless networks, ubiquitous computing, heterogeneous networks, and security as well as management aspects surrounding them. We encourage you to submit original papers describing research results or practical solutions. Paper topics include, but are not limited to:

 

Local Area Networks                           Network Management

Personal/Wearable Networks               Mobility Management

Embedded Networks                           Location-dependent Services

Wireless Networks                               Ad-hoc Environments

Home/SOHO Networks                       Network Traffic Characterizations

Network to the Home                           Performance Evaluation/Measurements

High-Speed Networks                          Quality-of-Service

Optical Networks                                 Congestion Control/Behavior Control

Storage-Area Networks                       Network Reliability

Peer-to-Peer Networks                        Network Security

Overlay Networks                                Adaptive Applications

 

The following workshops are held in conjunction with LCN:

 

- WLN: 5th International IEEE Workshop on Wireless Local Networks http://www.cse.unsw.edu.au/~wln2005/

 

- 1st IEEE International Workshop on Performance and Management of Wireless and Mobile Networks: http://www.site.uottawa.ca/~boukerch/IEEE-perf.html

 

- The IEEE LCN Network Security workshop:

http://www.cs.uvic.ca/~wkui/IEEE-WoNS.htm

 

 

 ‘From Around the TCCC ExCom’

 

The following Technical Brief was originally published in the May 2005 Newsletter. It was so well received, I thought I would include it in the November 2005 Newsletter for all the new TCCC members. The May 2005 submission was obtained through the efforts of Archan Misra, TCCC Un-tethered Network Technology Chair.

 

The brief “A-V of IEEE 802.11 Wireless LAN Protocols” is offered by Dr. Sai Shankar N. Sai received his PhD degree from the department of Electrical Communication Engineering from Indian Institute of Science, Bangalore, India in the area of ATM networks. He is currently a Researcher at Qualcomm. Prior to this, he was with Phillips Research USA, Briarcliff Manor, NY working in the area of Wireless LANs. He is an active contributor to and leader in various wireless LAN standards, such as 802.11e, 802.15.3 (Ultra-Wideband) and 802.11n.

=====================================

 

A-V of IEEE 802.11 Wireless LAN Protocols

Sai Shankar N, Qualcomm, USA, nsaishankar@qualcomm.com

 

Introduction:

 

Since the adaptation of IEEE 802.11 standard in 1997, it has been a remarkable success, which has seen its application range from data oriented computer communication to demanding multimedia applications such as voice and video. In response to growing applications and scarcity of limited unlicensed wireless spectrum, IEEE 802.11 has evolved over the years to use higher physical media transmission rates and cover additional unlicensed spectrum. The additional PHY layer protocols were developed to be compatible with the legacy IEEE 802.11 standard.

However, even as the wireless network was being widely deployed some weaknesses in the original MAC protocol got more scrutinized. For example, the WEP security mechanism in the protocol was shown vulnerable to attacks with the commonly available tools in as little as ten minutes. Secondly, in the European domains, there are some additional requirements on transmit power control and dynamic frequency selection which the original protocol did not address. Thirdly, looking at the future of the networking, real-time two-way and multimedia streaming applications took on increasing significance. While the IEEE 802.11 protocol was designed to provide good performance for data-centric applications, the legacy MAC protocol did not provide mechanisms to ensure QoS for the applications served. This article provides a simple overview of the current IEEE standard along with its amendments. Figure 1 illustrates the different amendments that have been already defined and the new amendments that would take few years to complete.

Figure 1: IEEE 802.11 standard and its amendments.

 

The IEEE 802.11 standard is an evolving standard as the legacy standard is continuously being amended to improve and address deficiencies mentioned above. Originally IEEE 802.11 standard was launched in 1997. The standard defined the MAC layer and three different physical layers. The original MAC is based on two coordination functions, namely, the Distributed Coordination Function (DCF) that is mandatory and the Point Coordination Function (PCF) that is optional. DCF is based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) and acknowledgement while the PCF works through polling. All of today’s 802.11 devices operate in the DCF mode only. In the DCF all devices listen to the channel to asses whether the channel is busy or not (this is also called as Clear Channel Assessment (CCA)) and waits for a random amount of time determined by the backoff process and then transmits the frame. If the frame is lost because of channel errors or collision, the transmitter doubles its backoff time value and then repeats the procedure outlined as before for a frame transmission.

 

IEEE 802.11 PHYSICAL LAYER

 

As mentioned earlier, the original MAC had three different physical layers that were based on Infra Red (IR), Direct Sequence Spread Spectrum (DSSS) and Frequency Hopping (FH). The IEEE 802.11 standard body added amendments in physical layer called IEEE 802.11a and IEEE 802.11b. The IEEE 802.11a operates in the 5 GHz band and has 8 different data rates ranging from 6 Mbit/s to 54 Mbit/s. The modulation is based on Orthogonal Frequency Division Multiplexing (OFDM). The IEEE 802.11b operates in the 2.4 GHz and has 4 different data rates ranging from 1 Mbit/s to 11 Mbit/s. In the year 2001, IEEE enacted a new amendment called as IEEE 802.11g that has the same modulation and data rates as IEEE 802.11a but operates in the 2.4 GHz. Currently IEEE is working on a new amendment called IEEE 802.11n that will use Multiple Input Multiple Output (MIMO) technology with a minimum data rate of 108 Mbit/s and the maximum exceeding 500 Mbit/s.

IEEE 802.11 MAC LAYER

 

Today, IEEE 802.11 can be considered a wireless version of Ethernet by virtue of supporting a best-effort service (not guaranteeing any service level to users/applications). To enhance the performance of today’s WLAN, the IEEE 802.11 working group amended a new standard called IEEE 802.11e that would support QoS. This is an extension of the current IEEE 802.11 legacy WLAN. Since the WLAN operation in 5 GHz interferes with radars that are primary users of 5 GHz spectrum the IEEE 802.11 amended IEEE 802.11h that mandates the IEEE 802.11 WLAN to move out of the current frequency if the radar is detected. This is called Dynamic Frequency Selection (DFS). This amendment also includes Transmit Power Control (TPC), which defines the levels of power that the WLAN network or some stations in the network should use to minimize interference. As already outlined in the introduction, the current Wired Equivalent Privacy (WEP) is broken and hence IEEE specified IEEE 802.11i that uses AES to get reliable data transfer, key exchange and ensure that the protocol is not prone to eavesdropping. In order to determine the optimal Access Point (AP) for association and the load on each BSS, IEEE 802.11 amended IEEE 802.11k that enables measurement of radio resources. IEEE 802.11n was amended to look for ways to enhance IEEE 802.11e to get throughputs starting from 108 Mbit/s. This standard is designed to use MIMO technology and is backward compatible with IEEE 802.11.To enable communication when devices using WLANs are in vehicles traveling in highways at speeds of 60 miles per hour or in trains traveling at 200 kilometers per hour, IEEE 802.11p enables inter vehicle communication as well as communication between vehicles and road side devices. This amendment is in progress and will be used in 5.8 GHz band in North America. IEEE 802.11r was established in order to enable seamless roaming between different WLAN networks, minimize the handoff latency and ensure QoS while performing handoff. In order to have a wireless mesh technology wherein the entire city can have a wireless connectivity without having to engineer to place the APs optimally, IEEE 802.11 amended the IEEE 802.11s. This would support broadcast, multicast and unicast data transfers at very high rates. IEEE 802.11t was amended in order to test the performance of different applications running over IEEE 802.11. This would device a common set of accepted performance metrics and measurement methodologies. IEEE 802.11u was formed to enable inter working with other wireless networks that would include frame exchanges at the protocol level and any primitives that would be required for this functionality at the higher layer level. IEEE 802.11v was formed to enable management of attached stations in a centralized or in a distributed fashion (e.g. monitoring, configuring, and updating).  This is different from IEEE 802.11k that does only measurements and not configuring and updating of any devices.

 

HIGHER LAYER FUNCTIONALITY

 

IEEE 802.11c provides required information to ensure proper bridge operations. This is used by product developers when developing access points. When 802.11 first became available, only a handful of regulatory domains (e.g., U.S., Europe, and Japan) had rules in place for the operation of 802.11 wireless LANs. In order to support a widespread adoption of 802.11, the IEEE 802.11d task group has an ongoing charter to define PHY requirements that satisfy regulatory requirements in additional countries. This is especially important for operation in the 5 GHz bands because the use of these frequencies differ widely from one country to another. The existing 802.11 standard does not specify how access points should communicate among themselves to support users roaming from one access point to another. Consequently, when roaming, baccess points from different vendors would frequently not inter-operate with one another. IEEE 802.11f thus specifies an inter-access point protocol that provides the necessary information that needs to be exchanged to enable efficient roaming. With the opening of new wireless bands for indoor, outdoor, and mobile use in Japan, the IEEE has approved an amendment to IEEE 802.11 to support the new spectrum and their designated applications. The amendment, IEEE 802.11j, will enable WLAN vendors to offer wireless products that adapt to new frequencies, different channel widths, and operating parameters.

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Please do not hesitate to contact me or any of the ExCom members if you have any questions or concerns regarding TCCC activities. In particular, we would love to have your feedback on what you would like to see in future Newsletters, and the online publications area of the TCCC web page with suggestions ranging from tutorial-style articles on emerging technical areas by experts to original research articles to reports on ongoing TCCC-related activities in different IEEE regions. Your feedback will enable us to serve our common interests in a more productive way.

 

Thank you,

 

Joe Bumblis

Chair, TCCC