Adaptive Multi-Channel Clustering in IEEE 802.11s Wireless Mesh Networks

WLAN mesh networks are one of the key technologies for upcoming smart city applications and are characterized by a flexible and low-cost deployment. The standard amendment IEEE 802.11s introduces low-level mesh interoperability at the WLAN MAC layer. However, scalability limitations imposed by management traffic overhead, routing delays, medium contention, and interference are common issues in wireless mesh networks and also apply to IEEE 802.11s networks. Possible solutions proposed in the literature recommend a divide-and-conquer scheme that partitions the network into clusters and forms smaller collision and broadcast domains by assigning orthogonal channels. We present CHaChA (Clustering Heuristic and Channel Assignment), a distributed cross-layer approach for cluster formation and channel assignment that directly integrates the default IEEE 802.11s mesh protocol information and operating modes, retaining unrestricted compliance to the WLAN standard. Our concept proposes further mechanisms for dynamic cluster adaptation, including subsequent cluster joining, isolation and fault detection, and node roaming for cluster balancing. The practical performance of CHaChA is demonstrated in a real-world 802.11s testbed. We first investigate clustering reproducibility, duration, and communication overhead in static network scenarios of different sizes. We then validate our concepts for dynamic cluster adaptation, considering topology changes that are likely to occur during long-term network operation and maintenance.

A Chosen Random Value Attack on WPA3 SAE protocol

Wi-Fi Alliance(WFA) recently standardized the new suites of security protocols, as known as WPA3, to enhance the Wi-Fi security, which includes the SAE protocol. SAE (Simultaneous Authentication of Equals), based on the Dragonfly key exchange protocol, is a password authenticated key exchange protocol, which has been ratified in Internet Engineering Task Force (IETF) RFC 7664. The SAE Authenti- cation Protocol was first submitted to the IEEE 802.11s (Wi-Fi Mesh Networks), and recently was successfully selected as a candidate security standard to become the next generation Wi- Fi security protocol, WPA3. The SAE key exchange protocol and its variants, i.e, the Dragonfly key exchange protocol and TLS-PWD, have received some cryptanalysis, in which the authors pointed out the Dragonfly protocol exists the sub- group attack vulnerability. In this paper, we also observed some vulnerability that could result in the impersonation attacks.

Hybrid LoRa-IEEE 802.11s Opportunistic Mesh Networking for Flexible UAV Swarming

Unmanned Aerial Vehicles (UAVs) and small drones are nowadays being widely used in heterogeneous use cases: aerial photography, precise agriculture, inspections, environmental data collection, search-and-rescue operations, surveillance applications, and more. When designing UAV swarm-based applications, a key “ingredient” to make them effective is the communication system (possible involving multiple protocols) shared by flying drones and terrestrial base stations. When compared to ground communication systems for swarms of terrestrial vehicles, one of the main advantages of UAV-based communications is the presence of direct Line-of-Sight (LOS) links between flying UAVs operating at an altitude of tens of meters, often ensuring direct visibility among themselves and even with some ground Base Transceiver Stations (BTSs). Therefore, the adoption of proper networking strategies for UAV swarms allows users to exchange data at distances (significantly) longer than in ground applications. In this paper, we propose a hybrid communication architecture for UAV swarms, leveraging heterogeneous radio mesh networking based on long-range communication protocols—such as LoRa and LoRaWAN—and IEEE 802.11s protocols. We then discuss its strengths, constraints, viable implementation, and relevant reference use cases.

Descriptive model for distributed element synchronization digital radio networks of the IEEE 802.11s and IEEE 802.11p standards

Today, the basic radio communication standards for building self-organizing networks such as MANET, VANET and FANET are IEEE 802.11s and IEEE 802.11p. The link layer is responsible for establishing and conducting a communication session in these networks. It includes a variety of procedures, the main of which are synchronization procedures, random multiple media access, reserved media access and transmitter power control of network elements. Moreover, in digital radio communication networks of the IEEE 802.11 standards family, both centralized synchronization and distributed synchronization of such network elements are used. However, in digital radio networks of the IEEE 802.11s and IEEE 802.11p standards, the key procedure for establishing and conducting a communication session is the distributed synchronization of the network data elements. It should be noted that there is no descriptive model of distributed synchronization of the IEEE 802.11s and IEEE 802.11p standards digital radio communication network elements, taking into account these standards features. All elements of the IEEE 802.11s and IEEE 802.11p digital radio network send Beacons on a competitive basis. This occurs cyclically at the start of the repeating sync interval. In this regard, the occurrence of three events is possible: successful transmission of the synchronizing Beacon packet, its collision with a similar packet and a service or user data packet. To prevent (reduce) the number of collisions in a digital radio communication network, it is necessary to maintain a constant time difference between the internal time of all network elements. It is worth noting that maintaining a constant time difference for all digital radio communication network elements through guaranteed and timely sending of synchronizing Beacon packets is the main mechanism for distributed synchronization of such network elements. In the event that the calculated value of the time difference Toffsetni for one of the neighboring elements of the digital radio communication network does not coincide with the analogous value obtained in the past synchronization interval Toffsetni-1, then the correction of the own internal TTSF time of the IEEE 802.11s and IEEE 802.11p standards digital radio communication network element begins. The procedure for adjusting the network element internal time continues until the maximum value of this element internal time offset TMaxClockDrift is equal to zero. Also, to reduce or prevent collisions of synchronizing Beacon packets in the data transmission channel, each network element both initially, when entering the network, and immediately when collisions of synchronizing packets occur, Beacon selects and sets the timing parameters of synchronization so that they do not coincide with similar parameters of neighboring network elements. The developed descriptive model of the IEEE 802.11s and IEEE 802.11p standards digital radio communication network elements distributed synchronization includes algorithms for the such network elements functioning, adjusting the such elements intrinsic internal time, searching for an alternative value for the start time of a repeating synchronization interval and adjusting it. The presented model is applicable in the development of analytical and simulation models for assessing the IEEE 802.11s and IEEE 802.11p standards digital radio communication network performance, taking into account the distributed synchronization of such network elements.

CARA-OHT: Collision-Aware Rate Adaptation for Optimal High-Throughput in IEEE 802.11s Wireless Mesh Networks

The wireless mesh network (WMN) is a future network technology that develops single-hop wireless local area networks (WLANs) into multi-hop wireless mesh networks, based on the IEEE 802.11s standard. However, this development still presents many challenges, such as determining the best route between sources and destinations, especially taking into account the use of the medium access control (MAC) and physical (PHY) layers of IEEE 802.11n/ac. Some papers have proposed rate adaptation algorithms particularly for single-hop networks; however, these only focused on mechanisms to find data rates suitable for channel conditions. In IEEE 802.11s WMNs, the design of the rate adaptation algorithm is more challenging. Besides considering the problem of channel quality and optimal throughput, it is necessary to also consider the problem of collision and the best route. It is important to take collision into account because the collision probability in multi-hop mesh networks is higher than that in single-hop networks and can lead to a lower throughput. Rate adaptation algorithms for IEEE 802.11s WMNs have been proposed in other papers, but they also do not consider the use of the MAC and PHY layers of IEEE 802.11n/ac. In this paper, we propose the collision-aware rate adaptation for optimal high-throughput (CARA-OHT) algorithm for WMN IEEE 802.11s. An evaluation through the extensive use of a network NS-3 simulator shows that the proposed algorithm exhibits a higher throughput than previously developed algorithms.

Secure Routing Algorithm in Wireless Mesh Network

In the today’s’ era of communication technology disaster management plays important role in life saving. Regardless of men made disasters or natural disasters proper communication network can be used to exchange information. In natural calamities wireless sensor mesh network proved to be as good option for communication. Low-altitude Unmanned Aerial Vehicles (UAVs) which is associated with WLAN Mesh Networks (WMNs) can be used in disaster management areas. The advantage of it is it can be installed on demand and it can use for efficient exploration of sized areas. The WMN is consisting of different components such as mesh clients, mesh routers and base station. It is more prone to have attacks of different types such as Denial of Service attack, black hole, gray hole , reply attack, Sybil attack etc. The most important attack which can damage whole working of WMN is routing attack. IEEE 802.11i is used as standard protocol for security in WLAN and IEEE 802.11s is used as secure algorithm for communication in WLAN mesh network. But both of them fail to address issue of routing problem in WLAN mesh network. The primary purpose of this paper is to outline routing algorithm and to design assured routing protocol. In this paper we have proposed improved secure Position-Aware, Secure, and Efficient mesh Routing approach (S-PASER). The proposed mechanisms have obviated more attack than regular IEEE 802.11s/i security mechanism and well known, secure routing protocol. The proposed methodology can be implemented on omnet++ simulator. The simulation results proved to be have better performance and throughput than existing algorithm.