IEEE Computer Society Technical Committee on Computer Communications
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 (email@example.com)
at the Computer Society by
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
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
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 (firstname.lastname@example.org) at any time regarding the TCCC, the Computer Society, or to simply chat.
IEEE International Symposium on a World
By: Archan Misra
The sixth IEEE International
Symposium on a World of Wireless,
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
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
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.
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 —
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:
‘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,
A-V of IEEE 802.11 Wireless LAN Protocols
Sai Shankar N, Qualcomm, USA, email@example.com
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.
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.
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
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.,
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.