Mind the gap: Working on wireless solutions

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Working on Wireless Solutions

Inaugural speech given by

Sonia Heemstra de Groot

Professor in Personal and Ambient Networking

Faculty of Electrical Engineering, Mathematics and

Computer Science

Delft University of Technology

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Mijnheer de Rector Magnificus, Leden van het College van Bestuur, Beste studenten,

Collegae hoogleraren en andere leden van de universitaire gemeenschap, Zeer gewaardeerde toehoorders,

Beste collegae, familie en vrienden, Dames en Heren,

I will continue my talk in English on behalf of my international colleagues and other foreign guests.

Wireless communication is an exciting field. In this talk I would like to convey to you my enthusiasm about this field and the role that I myself, with my colleagues and students at TU Delft intend to play in it.

The field is in full development. Besides creating opportunities for improving our lives, and contributing to the solutions of many of the problems the world is facing now, it offers opportunities for new business. The title of my talk is “Mind the gap”, hinting at the fact that there is something not completely smooth, which may prevent us from going where we want to go. The field is exciting and great. But it will only do what we want it to do, like helping to solve the imminent health care, security and infrastructure problems that the world is facing, if we are aware that academic research needs some extras to bridge the gap to real solutions. But let’s start with the enthusiasm.

In this presentation, I will talk about the developments that are going on in wireless networking and those that are likely to be expected in the future. I will pay special attention to the indispensable and increasing role that ad hoc networks will play in this evolution. Wherever appropriate, I will show the links with concrete activities at university and industry in which I am involved.

Evolution towards future wireless generations

Until recently, wireless communication used to be dominated by telecom operators. They were providing first analog wireless telephony, the so called 1G systems, later from the nineties on, the globally successful GSM or 2G

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systems and since a couple of years, the 3G systems, in Europe known as UMTS. In this process a shift occurred from voice services to data services. Lately, however, more players have started to enter the field with WLAN products, and consumer electronics equipped with short range technologies, such as Bluetooth. This has caused an evolution from wireless communication systems that use a single technology to a combination of different complementary technologies. The latter is characteristic for what are called Fourth Generation wireless systems, or 4G. 4G is not a single technology, but a combination of technologies that have been optimized for specific purposes and that comprises many different standards addressing a large variety of data rates and geographical coverage. A characteristic of 4G is therefore its large heterogeneity and, its continuous evolution. Let us take a closer look at 4G. 2G 9.6 - 144 kbps2G 9.6 - 144 kbps 3G + < 20 Mbps3G + < 20 Mbps 3G > 2 Mbps3G > 2 Mbps 100 Mbps?100 Mbps? 4G4G cdmaOne Cdma2000, HDR UMTS GSM EDGE

Always Best Connected

60 GHz radio Ad-hoc networks DVB/DAB Zigbee GPRS Bluetooth 1G 1G AMPS C-NETZ New air interfaces HSDPA WiFi WiFi WiMAx

UWB Cognitive_radio NMT Analog voice Digital voice Digital voice + data Full IP based

“Integrated wireless world”

TACS

MIMO

Figure 1: The evolution towards 4G.

4G is supported by a vast range of new technology components, which are the building blocks of 4G systems. Examples are techniques to improve the communications performance by the use of multiple antennas at both the transmitter and receiver (also known as MIMO) and dynamic adaptation of the operating frequency and other parameters according to the conditions of the environment (also known as cognitive radio). Regarding radio technologies, existing technologies such as IEEE802.11 (known as Wi-Fi),

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the various forms of IEEE802.15 (such as Bluetooth, Zigbee, etc.) and IEEE802.16 (also called WiMAX) are being enhanced to support higher data rates, deal with mobility of users, provide stronger security, and decrease power consumption.

At the same time new radio technologies such as IEEE802.22 are emerging that make use of intelligent techniques to re-use the spectrum that has been allocated to other purposes, as TV broadcasting (which is under-utilized) without interfering with the primary users. Equally important are developments on middleware for mobile computing, and techniques for the support of the seamless integration of heterogeneous networks.

Ad-hoc networks

A more fundamental development that will affect 4G profoundly is the widespread use of ad-hoc networking. Ad-hoc networks do not make use of infrastructure. "Infrastructure" is the part of the telecom systems that supports the mobile devices of the end user. So, the GSM infrastructure consists of the antennas with which our phones are in contact but also all the interconnections between the antennas, the computers, routers, interfaces to the fixed telephony system, etc. In the case of wireless LANs, the infrastructure contains the base stations, and the entire Internet to which the base stations interface.

Currently, most of the wireless technologies such as Wi-Fi are mostly used in infrastructure mode. This means that wireless devices always make use of pre-deployed access points and servers connected to the fixed network infrastructure. Even when two devices are within the coverage of each other they do no communicate directly, but via the access point in the infrastructure.

Unlike infrastructure networks, ad-hoc networks are a collection of nodes that form a self-organizing network without any support of an infrastructure: they do it all by themselves. For example, the nodes themselves need to discover the network topology and route and forward messages.

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Infrastructure mode Ad-hoc mode

Figure 2: Infrastructure versus ad-hoc mode.

Research in ad-hoc networking was originally mainly for military applications, where rapid network deployment in unfamiliar territory, coping with a hostile environment, and lack of any support from outside are some of the key characteristics.

However, in the last decade, with the introduction of low-cost wireless technologies, for instance IEEE802.11, Bluetooth, and Zigbee, the interest of the academic world has increased dramatically. Ad-hoc networks have become a main topic of network research.

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Most of this research focused on general purpose mobile ad-hoc networks, the so called MANETS, composed of nodes with similar capabilities, for instance using the same radios. These ad-hoc networks operate in isolation. The field has been very productive from the theoretical point of view, but there has been little interest from potential users and from industry. The main reason is the gap between the challenges addressed by the research community and the concrete needs of the applications. For example, a lot of attention was given to routing algorithms for the dynamically changing network topology in ad-hoc networks. This resulted in thousands of scientific papers and a proliferation of routing protocols without an absolute winner since the performance of each algorithm greatly depends on the scenario.

Ad-hoc networking solutions for the real world: the gap between

theory and practice

The lack of commercial success of general-purpose wireless ad-hoc networking can be attributed to the wide gap between the general purpose solutions, designed for “theoretical applications” and what is needed for real applications.

Ad-hoc networking started to have practical value at the moment that concrete applications were addressed. Instead of trying to solve all issues in a generic and academic fashion, attempts were made to close the gap between theory and practice. At the moment we can say that different ad hoc network technologies are commercially successful. Let us discuss some of these.

Wireless mesh networks

One of the examples showing market potential are definitely mesh networks. These are ad-hoc networks built by a combination of fixed and mobile nodes interconnected via wireless links. In a mesh network, each node acts as a router or repeater for other nodes in the network. The nodes can be fixed or mobile. This results in a decentralized and inexpensive mobile broadband network, since each node only needs to transmit as far as the next node, rather than to the ultimate destination.

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Internet Internet

Figure 4: Mesh network.

This technique allows the network to extend its coverage in a cost-effective way, span large distances, provide high data rates, and create non-line-of-sight connections over rough terrain or in urban areas.

In principle, mesh networking can be applied to practically any radio technology; Wi-Fi, WiMAX and UWB can be meshed. Wi-Fi is being used in many metropolitan mesh network deployments.

Wireless sensor networks

Another success story in providing real-world solutions is wireless sensor networks. The wireless sensor networks of the near future are envisioned to consist of hundreds to thousands of inexpensive wireless nodes, each with some computational power and sensing capability. They are intended for a broad range of sensing applications ranging from environment monitoring, health applications and factory process control to vehicle tracking, precision agriculture and military applications.

Sensor nodes are mostly battery powered. In order to minimize the energy consumption, the sensor nodes communicate with the base station or sink utilizing multi-hop wireless communication because this reduces the transmission power as well as the interference between devices. In addition, the sensor nodes often process and aggregate gathered data in order to

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reduce the number of packets that need to be sent and reducing further the energy consumption. Structure response Precision agriculture Vital sign monitoring Structure response Precision agriculture Vital sign monitoring

Figure 5: Sensor networks

The design of wireless sensor networks is strongly bound to the application which dictates the moment and the way the information has to be conveyed. As a result stronger multidisciplinary collaboration between communication researchers and engineers, and those involved in the specific application is required.

Wireless sensor networking is very successful from the research as well as from the commercial point of view. The area is very well represented in The Netherlands. Worth mentioning are the research carried out at TU Delft by the group of Koen Langendoen, the E-Sense and Cruise projects at our own WMC group and at the University of Twente in the group of Paul Havinga.

Emerging hybrid ad-hoc infrastructure networks

In addition to the examples of successful ad hoc networks we just discussed, many new applications are emerging that benefit from hybrid networks consisting of ad hoc and infrastructure parts. This is where the future lies, and where we will be conducting our research. The examples that concern us most are: vehicular networks, personal networks, fednets and ambient networks.

Vehicular networks

It is envisaged that in the not too distant future, new cars will be equipped with capabilities for communicating with other nearby vehicles as well as

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with base stations located on the roadside, forming what is known as “vehicular networks”. Vehicular networks open a wide spectrum of applications ranging from road safety and efficient traffic management to in-car entertainment. For example, by exchanging sensor information with nearby cars, dangerous situations, such as bad road conditions, unexpected driver behavior, sudden traffic jams, etc. may be detected and even automatically acted upon at a very early stage, preventing accidents.

services

Figure 6: Vehicular network for road safety

Vehicular networks pose a number of challenges, in particular when dealing with safety-critical applications. Some of these challenges are being addressed in several R&D projects, including the European project HIDENETS1 in which we are participating.

From PAN to PN

Some of you are undoubtedly already familiar with personal area networks or PANs. A PAN is a special case of ad-hoc networks that allows communication between portable and mobile computing devices located in the close vicinity of a person. Typical devices are cellular phones, laptops, PDA, headphones, network peripherals, cameras, etc. Bluetooth is the most commonly used radio technology for this purpose complemented by Zigbee for connecting small sensors

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Home cluster Corporate cluster Infrastructure networks (GSM, UMTS, WLAN, PSTN, …) Vehicular area network Remote nodes Ad-hoc networks PAN Home cluster Corporate cluster Infrastructure networks (GSM, UMTS, WLAN, PSTN, …) Vehicular area network Remote nodes Ad-hoc networks PAN PAN

Personal area network (PAN)

Personal network (PN)

Figure 7: From personal area network to personal network.

In the near future, the local scope of the personal area network will be extended automatically to include other devices belonging to the user, located at remote locations such as the home, car or office. This transparent extension of the PAN will physically be made via infrastructure-based networks such as an organization’s intranet, mobile networks, and the Internet. The resulting network is known as personal network or PN.

The advantages of PNs will become more obvious as the number of personal devices increases. Observe that although nowadays we have just a few devices, in the near future this number is expected to increase tremendously. It is predicted by the Wireless World Research Forum or WWRF2 that, 10 years from now, there will be 7 trillion wireless devices serving 7 billion people, that is, on the average 1000 wireless devices per person.

Therefore Personal Networks can be seen as a Next Generation Networking concept, that allows to organize a big part of these devices to make them cooperate in an effective way.

Extending the scope of PNs

The personal space of the user will extend to interact with other persons as well as with her environment.

2_{Nigel Jefferies, “Global Vision for a Wireless World”, Wireless World Research Forum, 18}th

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In the first case, personal networks will be able to temporarily federate in a group centric manner by allowing the group members to access a subset of specific services. These temporary ad-hoc federations are known as fednets3. This concept is particularly useful when a group of PNs needs to cooperate in a quick manner to reach a common goal.

Home network Corporate network Interconnecting structure Vehicular area network Home network PN2 PN1 PN3 Figure 8:Fednets

An example is an emergency operation involving professionals, such as fire fighters, policemen, medical personnel, and environmental specialists. Each professional, as part of her individual PN has a diversity of devices to assist her in monitoring and observing, as sensors, cameras and communication equipment. A fednet would allow to share these monitoring and observation devices to enhance the capabilities of each professional involved, e.g., to give the policeman or medical personnel a view of the situation inside a burning building by using helmet-mounted cameras of firemen.

3_{I.G. Niemegeers and S.M. Heemstra de Groot, “FEDNETS: Context-aware Ad-hoc Network}

Federations”, International Journal on Wireless Personal Communications, Volume 33, June 2005, pp.319-325

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The concepts of personal networks as well as fednets have been proposed by my colleague Ignas Niemegeers and myself in 2002. They have been the basis for several large research projects: The Dutch projects QoS in Personal Networks at Home and PNP2008 and the European IST projects Magnet and Magnet Beyond.

Currently one of my Ph.D. students is investigating solutions for controlling the access to the personal resources in dynamic Fednets

Hybrid networks for support of emergency operations

A further example of the potential of combining ad-hoc networks with infrastructure can be found in the area of disaster relief operations.

Consider a hybrid network in a disaster relief scenario, for example a large industrial fire, where several instances (medical, police, fire and rescue) cooperate to extinguish the fire, protect the people, limit environmental damage and the impact on the operational activities in the area.

Decision and actions are taken on the basis of expertise as well as on the basis of observing and sensing. The network will comprise ad-hoc communication capabilities between vehicles, but also a wide range of sensing systems, such as quickly deployed sensors to measure the presence of toxic gases and high temperatures in the incidence area, sensors attached to emergency workers, including cameras, mobile robots with sensors, and information processing units.

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Remote control center Medical expertise center Environment expertise center Remote experts Structure experts Local control center Temporary mesh units Fire team Robot Police team Trauma team

Figure 9: combination of ad-hoc and infrastructure networking in a disaster relief operation.

Although a large part of the ad-hoc network is located in the incidence area such an operation requires communication with command and control centers, as well as with specialized expertise centers that may be located remotely, for instance, centers for environmental analysis, medical expertise, and structural expertise. The information from the incidence area may have to be analyzed in real-time at these centers. This may require high quality images and video.

We are currently investigating many of the issues that need to be solved to make this vision reality.

Hybrid networks for restoration of critical infrastructures

Another interesting application of hybrid networks is for the restoration of critical infrastructures. When a large disaster occurs, for instance an earthquake or flooding, the network may become partially disconnected, leaving islands with still functioning nodes and links but isolated from each other. Other infrastructures in the affected area may also be severely

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impacted. For example, it may be that both wired and wireless infrastructures have failed and that the road and power infrastructure is affected. The process to restore the network to normal operation may be difficult and lengthy; it might take months to restore or rebuild the original networks. The effect on many other infrastructures may be disastrous, e.g., the financial and banking infrastructure may be down, paralyzing economic activities.

Hybrid ad-hoc infrastructure networks may offer an effective solution for restoring, in a timely fashion, communication infrastructures that have been massively disturbed. This is a prerequisite to make society function again at an acceptable level and, for instance ensure business continuity.

We have proposed at TU Delft together with my company TI-WMC and the University of Aalborg the following approach, which has attracted the attention of the banking sector to ensure business continuity in times of disaster. In a situation of massive failure affecting multiple core-network components, broadband connectivity could be restored by deploying special ad-hoc nodes to reestablish, in a fully autonomous way, connectivity in the affected areas. As these ad-hoc networks are automatically fused with the still intact parts of the original core-network, the result is a hybrid (mixed-wired-wireless) network used for core-network broadband connectivity.

Network with multiple simultaneous failures Hybrid wired-wireless network for temporary restoration of connectivity Affected area Core network Disconnected islands Disconnected islands Affected area Affected area Core network Disconnected islands Disconnected islands Affected area Core network DRAN DRAN Core network DRAN DRAN DRAN DRAN Disaster Recovery Unit (DRU) Disaster Recovery Unit (DRU) Affected unit Affected link Affected unit Affected link

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Opportunistic networking

We can consider other applications of ad-hoc networks in which even more of the original constraints are relaxed. This is the case for opportunistic networking4.

Traditional communication networks are based on the concept of end-to-end connectivity. In order for B to be able to receive a packet sent by A, a path in the network between A and B should exist. Nodes that are temporarily disconnected from the network cannot communicate.

A

B

A

B Connected network

Opportunistic networking in disconnected network Figure 11: Opportunistic networking

Opportunistic networking is based on a different paradigm. Communication is possible even if a sender-receiver path does not exist. Communication is multi-hop with intermediate nodes storing the message and waiting to forward it until the opportunity to connect to a node, that gets close enough, arises. In contrast to traditional connected networks in which mobility is experienced as harmful because it causes route breakage, opportunistic networking takes advantage of mobility by exploiting the contact opportunities between mobile devices to forward information.

Opportunistic networking can be used to provide e-mail services in developing countries that cannot afford an infrastructure to provide continuous Internet access. A concrete example is the DakNet5 project. It

4_{L. Pelusi, A. Passarella, and M. Conti, “Opportunistic Networking: Data Forwarding in}

Disconnected Mobile Ad Hoc Networks,” IEEE Communication Magazine, Dec. 2006.

5_{A. Pentland, R. Fletcher, and A. Hasson, “DakNet: rethinking Connectivity in Developing}

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targets rural areas in India where low-cost village kiosks equipped with digital storage and wireless communication periodically exchange data with public transportation busses equipped with mobile access points.

Another application that is a perfect application of opportunistic networking is wildlife monitoring where human intervention should be minimized as much as possible. The Zebra Net project6 is an example of multidisciplinary research involving the disciplines of biology and computer science to study the use of opportunistic networking concepts for the study of animal migrations and inter-species interactions.

ZebraNet Wildlife monitoring Wildcense SWIM village kiosk mobile hot spot village village kiosk kiosk Internet access point city

Intermittent Internet connectivity

Figure 12: Applications of opportunistic ad-hoc networking

Opportunistic networking for nano technology

Opportunistic networking may well be the approach to support communications with micro and nano-devices. Nano technology offers the possibility to reduce the size of devices to dimensions comparable or even smaller than molecules.

Recently a fully functional, fully integrated radio receiver including all major components of a radio: antenna, tuner, amplifier, and demodulator has been constructed by researchers at the University of California at Berkeley7.

6_{http://www.princeton.edu/~mrm/zebranet.html}

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This radio is 10000 thinner than a human hair, and it is an example of what we can expect in the future.

These devices can be introduced in the bloodstream and be used for many different health applications. These devices need to receive information, exchange information for controlling their actions and collect data they have gathered. However they are able to communicate only with entities that are at a microscopic distance. Opportunistic networking seems to be a promising approach here.

Nano tube radio

Radio-controlled devices small

enough to exist in a human's bloodstream

Figure 13: Opportunistic networking for nano-devices

The future wireless world

After this tour of applications of ad-hoc networks, I would like to discuss the impact that ad-hoc networking will have in 4G.

Ad-hoc will play a major role in the future wireless world not only by extending the reach of the infrastructure but also in providing global connectivity to the billions of professional and consumer devices and sensors that will be “Internet-enabled” in the coming decade. They will make possible what is called “The Internet of Things”8.

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At present, almost all computing devices appearing on the market, as well as a large part of the gadgets we buy include wireless communication facilities. Just check the catalogue of a company like Media Markt or any retail store oriented towards lifestyle and entertainment. This as we all know is the result of the continuing advances in micro- and soon nano-electronics, captured by Moore’s Law. The number of networked devices will dramatically grow in the coming years. These devices will be mainly talking to each other, doing useful and good things for people, hopefully. People will not be aware of this Internet of Things.

From a technical point of view, this will result in communication scenarios comprising a combination of many infrastructure and infrastructure-less systems, involving many different technologies and with devices with a large disparity in processing and communication capabilities, energy constraints and availability. Infrastructure-supported ad-hoc networks or hybrid networks will provide the communication needs of the future wireless world, and will become the motor of 4G.

PAN sensor network Sensor network BAN home network emergency network VAN Access Networks ad hoc network corporate network mesh network Global

Figure 14: Ad-hoc networks in the future wireless world.

For us, network engineers, these developments have also major implications in the way the network resources are managed and controlled. Traditionally, wireless systems have followed a centralized approach. With the exception

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of the user terminal equipment, the rest of the equipment has been under the control of a network operator, traditionally large professional organizations with licenses to make use of expensive dedicated spectrum resources and utilizing expensive professional equipment. This model gave the operator full freedom to dimension and deploy the network and, to control the way the resources are used. The user put his full trust in the operator, and paid for it. As a result, such networks offer a high level of quality, availability, security and trustworthiness in general.

The advent of 4G and its proliferation of hybrid networks changes all this. Most of the networks that are part of this 4G fabric will have a spontaneous and temporary character beyond the management and control of professional organizations: they will do their own thing. However, they will have to share the scarce wireless resources with all other users in the proximity and this, without any centralized coordination! Besides sharing the radio spectrum, cooperation between unknown parties will be needed; devices belonging to different people, will need to cooperate, for instance to get connected to Internet, if their own radio interfaces cannot reach the infrastructure access points. How to achieve this cooperation? What safeguards are needed? What incentives can be used? These are challenging questions, for which there are no good answers yet. Security, one of the most crucial concerns nowadays, needs to be taken care of without the involvement of a central trusted authority.

Mitigating interference in multi-hop communications

The broadcast nature of wireless communications results in the transmission of energy that is received not only by the intended recipient but also by all nodes in the proximity, resulting in interference.

In multi-hop communication this problem results in a drastic reduction of the end-to-end throughput as the number of hops increases. This has motivated a lot of research in techniques to increase throughput by making more efficient use of the spectrum and mitigating the effects of interference.

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Transmission range 12 steps for 4 packets A A B C 6 steps for 4 packets

Single radio single-channel

Dual radio triple-channel

Transmission range 12 steps for 4 packets A A B C 6 steps for 4 packets

Single radio single-channel

Dual radio triple-channel

Figure 15 : Increase of throughput in multi-hop mesh networks by using multi-radio multi-channel nodes

A way to alleviate this problem is the use of several radios and multiple channels to allow parallel transmissions. Mesh networks traditionally operate using a single radio and a single channel. In a situation as shown in the figure above, only one transmission can take place at the time. Sending four packets from A to B would require 12 serial transmissions. If instead dual radios and multiple channels are used, parallel transmissions are possible resulting in fewer steps and therefore an increase of the overall throughput.

Multi-radio node (TI-WMC) Multi-radio antenna (TUD) Multi-radio node (TI-WMC) Multi-radio antenna (TUD)

Figure 16: High performance ad-hoc networking components from the Dutch project AAF

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This technique has been successfully implemented in the radio multi-channel adaptive network investigated in the Dutch Freeband AAF project, where TU Delft, the University of Twente and TI-WMC are participating. The figure shows a radio node developed at TI-WMC and a multi-radio antenna system designed and implemented by TUD.

Dealing with heterogeneity in the access

As mentioned before, 4G is not a single technology, but the combination of many complementary technologies in terms of transmission rate, radio coverage and power consumption. This heterogeneity should be hidden to the end-user. From the point of view of the end-user there should be a single communication network. From the engineering point of view this requires the seamless integration of the different technologies such that communication devices will be able to automatically select for the most suitable technology to connect.

IP multimedia subsystems

Internet mobile core

satellite

Broadcast

DVB-T/DAB UMTS/ HSDPA

WiMAX hotspot GSM/EDGE IEEE802.11 a/b/g IP multimedia subsystems IP multimedia subsystems Internet mobile core satellite Broadcast

DVB-T/DAB UMTS/ HSDPA

WiMAX hotspot GSM/EDGE

IEEE802.11 a/b/g

Figure 17: integration of heterogeneous radio access technologies in 4G.

An example is the integration of a variety of complementary technologies as Wi-Fi, WiMAX and Broadcast (as DVB-H) in the UMTS network. We have been doing work, together with one of my PhD students in this area as part of the Dutch Beyond 3G project.

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Security is an important concern in future wireless networks since any vulnerability will limit their practical use. Security is a concern in wireless systems because of the broadcast characteristics of the wireless medium that makes the channel particularly vulnerable to eavesdropping and active attacks. For instance an attacker can modify the contents or impersonate a legitimate user. Mobility introduces extra problems, since devices must be able to roam across wireless networks belonging to different administrative domains. Eve Trudy Alice Bob Modification Impersonation Authorized access Fabrication Replay Eavesdropping Traffic analysis

Figure 18: security threats in wireless communications

Additional problems arise in ad-hoc networks because of the lack of central authority to distribute keys or certificates. This introduces major challenges, in particular regarding authentication. Without being sure we are communicating with the right party, other security services as confidentiality (encrypting the message) and integrity (assuring that the message has not been modified) have no meaning.

Other demanding challenges appear when dealing with personal, ambient networks and other applications characterized by the use of multiple small devices with many of them constrained in terms of connectivity, computational power and energy budget. This requires solutions that are significantly different from those in traditional network security that were

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designed for powerful workstations operating with some sort of infrastructure support.

One of my PhD students has been researching these issues within the context of the IOPGenCom project QoS in PN at Home9 resulting in a security architecture for personal networks that does not require asymmetric cryptography10.

Wireless network security is a crucial and underexposed area. Therefore I am preparing, together with a colleague, a course on the topic, to be taught shortly.

Concluding remarks

In my talk I made the point that research aimed at finding technical solutions to problems in the real world, is not effective if carried out in isolation, starting from a single abstract view of reality. That leads to solutions which may have academic appeal and beauty, but do not solve real world problems. What is needed, is multiple views of the complete context in which a problem arises.

In order to close the gap between academic research and solving real-world problems, multidisciplinary research is necessary involving not only the classical mix of telecommunications, computer science, microelectronics, and mathematics but, depending on the problem domain, also sciences such as biology, medicine, sociology, psychology, logistics and business science. In order to achieve this, it is important to encourage the cooperation between different communities that are not naturally used to work together. This could be carried out by funding large, application-oriented multidisciplinary projects that have ambitious goals.

Concerning research methodology, in our field, theoretical research is not enough; it needs to be complemented by experimental research. Prototypes need to be built and experimented with. The best of abstractions are still, exactly that: abstractions of reality, trying to capture the essentials and

9_{QoS for Personal Networks @ Home, http://qos4pn.irctr.tudelft.nl/}

10_{Jehangir and S. M. Heemstra de Groot , “Securing Personal Network clusters” , International}

Conference on Security and Privacy in Communication Networks (SecureComm 2007), September 17-20, 2007, Nice, France.

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leaving out the seemingly unimportant. But almost always there are hidden aspects that are not captured by our models or that are, as yet, unknown and show up during experiments. This thinking is well present in the Internet community. Remember the adage of Dave Clark, an architect of the Internet; talking about new IETF standards being proposed; he said the famous words: “We reject: kings, presidents and voting. We believe in: rough consensus and running code”.

We are happy to do our research at TU Delft in the context of the IRCTR, where the building of prototypes and experimental research is advocated as essential to close the gap between academic research and solving real-world problems.

The university has recently defined a number of strategic application domains for research: health care, infrastructure, energy and, the environment. They are inspired by major challenges that are facing not only this country, but the whole world. We fully support the fact that these choices have been made and the strategy to organize the TU Delft research around these themes. We are convinced that for each of these themes, information and communication technology or ICT is an essential component of the solution. Why? For example, consider the problem of keeping overloaded road-, rail- and energy-infrastructures from collapsing, of keeping health care and the care for the elderly affordable, or being prepared for dealing with disaster. Technical solutions require gathering information on a large scale, sophisticated control and decision making processes often in real-time, and, controlling the actors, people and devices in the field. These are major and complex ICT problems, contrary to popular belief, not solved by off-the-shelf technology. They require a large research effort. All will involve hybrid networks to provide for the vast communication needs. This is an area where there is an opportunity for funding of challenging multidisciplinary projects that close the gap between academic research and solving real-world problems.

Needless to say that in our field, which is engineering oriented, we should aim not only at high quality scientific papers, but also at the valorization of our scientific results. We fully support the strategy of the university in this respect. We believe that true innovation will come less and less from established large industries, which have more and more responsibility towards their shareholders, financial organizations that demand short term returns. Innovation instead will have to come increasingly from start-ups,

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centered on universities where the bright and creative minds should develop ideas undisturbed by short-term business constraints.

Regarding education, we have the opinion that closing the gap starts right here. We should not only teach our future engineers, the scientific and technical disciplines to find principal solutions for well-defined problems in their domain of expertise. We should make sure that they are involved in building systems and experimenting with them. They should be exposed to dealing with wider problems in a multidisciplinary team. They should develop an entrepreneurial spirit by seeing value in creativity.

Finally, I cannot avoid to mention, in my condition of woman and, coming from another country, that I have been always surprised by the extremely low female participation in science and technology in The Netherlands compared to other countries in Europe and the world. I am very happy to see that this problem is receiving more and more attention. In particular I would like to praise the efforts of TU Delft in increasing the share of women in scientific positions. TU Delft of all technical universities is leading with a large margin in the number of female professors: congratulations. However, still, in the assistant and associate professor ranks, women are very rare: so, work needs to be done.

Closing

I will try to follow the protocol in not giving an extended acknowledgement. There are many people I would need to acknowledge. Forgive me for not doing it here. However I make an exception in expressing my gratitude to the authorities of the Technical University of Delft for having given me the opportunity to carry out research and education in such an excellent environment. And, I would like to thank the members of the Telecommunications department for the warm welcome and support they have given me. I am looking forward to bridging the gap with your help. Thank you