Large-Scale Distributed Internet-based Discovery Mechanism for Dynamic Spectrum Allocation

Scarcity of frequencies and the demand for more bandwidth is likely to increase the need for devices that utilize the available frequencies more efficiently. Radios must be able to dynamically find other users of the frequency bands and adapt so that they are not interfered, even if they use different radio protocols. As transmitters far away may cause as much interference as a transmitter located nearby, this mechanism can not be based on location alone. Central databases can be used for this purpose, but require expensive infrastructure and planning to scale. In this paper, we propose a decentralized protocol and architecture for discovering radio devices over the Internet. The protocol has low resource requirements, making it suitable for implementation on limited platforms. We evaluate the protocol through simulation in network topologies with up to 2.3 million nodes, including topologies generated from population patterns in Norway. The protocol has also been implemented as proof-of-concept in real Wi-Fi routers.Comment: Accepted for publication at IEEE DySPAN 201

Resilient internetwork routing over heterogeneous mobile military networks

Mobile networks in the military tactical domain, include a range of radio networks with very diverse characteristics and which may be employed differently from operation to operation. When interconnecting networks with dissimilar characteristics (e.g. capacity, range, mobility) a difficult trade-off is to fully utilize the diverse network characteristics while minimizing the cost. To support the ever increasing requirements for future operations it is necessary to provide tools to quickly alter the rule-set during an ongoing operation, due to a change in operation and/or to support different needs. Our contribution is a routing protocol which targets these challenges. We propose an architecture to connect networks with different characteristics. One key point is that low capacity links/networks segments can be included in the heterogeneous network, these segments are protected from overload by controlling where and when signaling/data traffic is sent. The protocol supports traffic policing, including resource reservation. The other key point is the ability to quickly alter the network policy (rules-set) including QoS support during an operation or from operation to operation.author postprin

ATM as a memory interconnect in a Desk Area Network

ATM has been successfully used in Wide Area Networks (WAN) and Local Area Networks (LAN). A possible next step in this evolution is to use ATM for cluster and desk area networks and to replace busses used for memory interconnect. This paper discusses how ATM can fulfill the functional and performance requirements in a memory interconnect, and the implications this will have for external ATM communication. We conclude that ATM can be used as a memory interconnect. It can meet the throughput requirements but will have problems with the latency requirements for the transfer of small cache lines. The fixed 48 byte payload in ATM results in inefficient use of bandwidth and increased latency. The ATM and the ATM Adaptation Layers do not have sufficient functionality and must be extended to offer the functionality required by the memory interconnect. Using ATM internally in the memory interconnect has a limited synergy effect when the system is connected to an ATM based LAN or WAN. 1. Introdu..

A Survey of 802.15.4 TSCH Schedulers for a Standardized Industrial Internet of Things

Concepts such as Industry 4.0 and Cyber-Physical Systems may bring forward a new industrial revolution. These concepts require extensive connectivity far beyond what is provided by traditional industrial networks. The Industrial Internet of Things (IIoT) bridges this gap by employing wireless connectivity and IP networking. In order for wireless networks to meet the strict requirements of the industrial domain, the Time Slotted Channel Hopping (TSCH) MAC is often employed. The properties of a TSCH network are defined by the schedule, which dictates transmission opportunities for all nodes. We survey the literature for these schedulers, describe and organize them according to their operation: Centralized, Collaborative, Autonomous, Hybrid, and Static. For each category and the field as a whole, we provide a holistic view and describe historical trends, highlight key developments, and identify trends, such as the attention towards autonomous mechanisms. Each of the 76 schedulers is analyzed into their common components to allow for comparison between schedulers and a deeper understanding of functionality and key properties. This reveals trends such as increasing complexity and the utilization of centralized principles in several collaborative schedulers. Further, each scheduler is evaluated qualitatively to identify its objectives. Altogether this allows us to point out challenges in existing work and identify areas for future research, including fault tolerance, scalability, non-convergecast traffic patterns, and hybrid scheduling strategies

A Survey of 802.15.4 TSCH Schedulers for a Standardized Industrial Internet of Things

Concepts such as Industry 4.0 and Cyber-Physical Systems may bring forward a new industrial revolution. These concepts require extensive connectivity far beyond what is provided by traditional industrial networks. The Industrial Internet of Things (IIoT) bridges this gap by employing wireless connectivity and IP networking. In order for wireless networks to meet the strict requirements of the industrial domain, the Time Slotted Channel Hopping (TSCH) MAC is often employed. The properties of a TSCH network are defined by the schedule, which dictates transmission opportunities for all nodes. We survey the literature for these schedulers, describe and organize them according to their operation: Centralized, Collaborative, Autonomous, Hybrid, and Static. For each category and the field as a whole, we provide a holistic view and describe historical trends, highlight key developments, and identify trends, such as the attention towards autonomous mechanisms. Each of the 76 schedulers is analyzed into their common components to allow for comparison between schedulers and a deeper understanding of functionality and key properties. This reveals trends such as increasing complexity and the utilization of centralized principles in several collaborative schedulers. Further, each scheduler is evaluated qualitatively to identify its objectives. Altogether this allows us to point out challenges in existing work and identify areas for future research, including fault tolerance, scalability, non-convergecast traffic patterns, and hybrid scheduling strategies

A Survey of 802.15.4 TSCH Schedulers for a Standardized Industrial Internet of Things

Concepts such as Industry 4.0 and Cyber-Physical Systems may bring forward a new industrial revolution. These concepts require extensive connectivity far beyond what is provided by traditional industrial networks. The Industrial Internet of Things (IIoT) bridges this gap by employing wireless connectivity and IP networking. In order for wireless networks to meet the strict requirements of the industrial domain, the Time Slotted Channel Hopping (TSCH) MAC is often employed. The properties of a TSCH network are defined by the schedule, which dictates transmission opportunities for all nodes. We survey the literature for these schedulers, describe and organize them according to their operation: Centralized, Collaborative, Autonomous, Hybrid, and Static. For each category and the field as a whole, we provide a holistic view and describe historical trends, highlight key developments, and identify trends, such as the attention towards autonomous mechanisms. Each of the 76 schedulers is analyzed into their common components to allow for comparison between schedulers and a deeper understanding of functionality and key properties. This reveals trends such as increasing complexity and the utilization of centralized principles in several collaborative schedulers. Further, each scheduler is evaluated qualitatively to identify its objectives. Altogether this allows us to point out challenges in existing work and identify areas for future research, including fault tolerance, scalability, non-convergecast traffic patterns, and hybrid scheduling strategies