IEEE Computer Society Technical Committee on Computer Communications
Welcome from the Chair – Joe Bumblis
Welcome to the May, 2005 TCCC
newsletter. There are many exciting events to share with you - the TCCC
membership. First, Klara Nahrstedt,
Bin Yu and Jin Liang of the
Second, there are several conferences sponsored by the TCCC that are either in their “Call for Papers” phase, or in their “Call for Participation” phase. These conferences and their call dates are included below.
Third, in an effort to keep our membership updated of current and evolving technological standards, we present an overview articles by an expert on 802.11 LAN technology on the various current and future standards on high-speed WLANs.
I invite all of you to visit the TCCC web page and review the information currently available. As we progress through 2005, many additional offerings will appear for your educational and enlightenment activities.
IEEE Conference on Pervasive Computing (PerCom) Conference Report
The Third IEEE International Conference on Pervasive Computing (PerCom 2005) was held at the Sheraton Kauai Resort on the beautiful sunny Poipu beach of the Kauai Island, Hawaii. As in the past, the conference activities focused on the emerging area of pervasive computing and communications aimed at providing an exciting platform and paradigm for all the time, everywhere services. The conference call for papers received overwhelming response with 240 papers submitted. The international technical program committee consisting of 53 researchers selected 31 top quality full papers and 8 concise contributions for oral presentations at the conference. In addition, the conference comprised seven workshops, two keynote speeches, two panels and a demonstrations session. Percom 2005 along with its seven workshops drew a total of 225 participants from 22 countries, over the five days of the conference events.
The main conference technical
sessions started on Wednesday, March 9, with a keynote titled “Beyond global
communications: The Active World” by Dr. Roy Campbell from
Besides the keynotes, two panels, both moderated by Dr. Taieb Znati discussed two of the hot issues in the pervasive computing community. The first panel was on “Trustworthiness in Pervasive and Ubiquitous Environment” and the panelists were Roy Campbell, Mani Srivastava, David Wagner, Fabio Martinelli and Sri Kumar. Some interesting questions included “What are the solutions to risks?” and “Is there an inherent relationship between trust and usability?”. Klara Nahrstedt raised the issue of “cost of trust”, and the panel agreed on the importance of cost-benefit analysis and cost-trust balance. The second panel focused on “Challenges and Opportunities of Pervasive and Ubiquitous Computing in Health Care”. The panelists were Kathy J. Liszka, Jay Lundell and Loren Schwiebert. The panel dealt with long-term challenging research problems that need to be solved to enable ubiquitous care, and technological barriers that need to be addressed for the development of a large scale pervasive and ubiquitous infrastructure for healthcare. Long standing challenges including energy, security, real-time issues, reliability, and ergonomics of medical devices were explored. Many questions were discussed during the panel, such as problems of liability and standardization that are prohibiting the proliferation of many health care systems.
PerCom 2005 comprised eleven regular sessions, covering various aspects of pervasive computing, including pervasive applications, context and location management, middleware platforms, security, mobile services, pervasive devices, energy efficiency, service discovery, sensor and wireless networks, etc. Some highlights include: Peng Zhou, et. al from University of Maryland and Rutgers University presented EZCab, which targets cab booking in dense urban areas using short range wireless communications; Gopal Pingali et al. from IBM Research presented their work on a pervasive chronicling system that allows a user to record and share an entire lifetime of experiences into a pocket-sized storage device; Matthias Grossmann from University of Stuttgart presented their Nexus platform, which is a scalable infrastructure for context data management. Nexus integrates multiple specialized context servers rather a central server, and provides a single common interface (Augmented World Query Language) for performing a query across multiple servers.
The Mark Weiser
best paper session was one of the highlights of the conference. The best paper
award was presented to the paper, Sizzle: A Standards-based end-to-end Security
Architecture for the Embedded Internet, authored by Vipul
Gupta, Mathew Millard, Stephen Fung, Yu Zhu, Nils Gura, Hans Eberle, Sheueling and Chang Shantz. The paper presented a small-footprint
implementation of the HTTPS stack called Sizzle, which needs less than 4kb of
RAM. Sizzle uses Elliptic Curve Cryptography (ECC), which makes public key
cryptography feasible on resource-constrained devices such as
The seven workshops focused on specific aspects of pervasive computing ranging from security in pervasive computing and communications (PerSec), middleware support for pervasive systems (PerWare), sensor networks and systems for pervasive computing (PerSeNS), context modeling and reasoning (CoMoRea), mobile peer-to-peer computing (MP2P), pervasive wireless networking (PWN), to pervasive learning (PerEL).
Elsevier’s new Journal on Pervasive and Mobile Computing (PMC) was announced at the conference. A special issue of PerCom 2005 selected papers will appear in Special Issue of PMC in early 2006.
The success of PerCom 2005 can also be attributed to the beautiful scenery
Next year, the Fourth IEEE
International Conference on Pervasive Computing will be held in
Authors: Klara Nahrstedt and Mohan Kumar served as the program and general chairs respectively. Bin Yu and Jin Liang served as student volunteers.
Upcoming Conferences/Workshops Sponsored by the TCCC
The Second IEEE Workshop On Embedded Networked Sensors (EmNetS-II)
Call for Participation (http://www.cse.unsw.edu.au/~emnet/)
[Co-sponsored with the
University of New South Wale, National ICT
The Second IEEE Workshop on Embedded Networked Sensors (EmNetS-II) will bring together researchers working in the broad area of embedded, networked sensors. The goal of the workshop is to promote community-wide discussion of ideas that will influence and foster continued research in the field. The workshop will provide a venue for researchers to present new ideas that have the potential to significantly impact the community in the long term, especially those exploring how practical considerations or novel application scenarios and requirements shape the design of these embedded and sensor networks.
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
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
Shankar N, Philips Research
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.