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The VST-TDMA access protocol has shown to have many advantages over existing protocols in centralized (star) wireless network architectures. As most data-link layer protocols, it does not have a recovery feature as data integrity is supervised by the connection-oriented transport protocols. Nevertheless, VST-TDMA possesses the flexibility to easily incorporate a retransmission feature that allows...
Standalone Long Term Evolution in unlicensed band (SA LTE-U) is a promising technology to address the scarcity of licensed band. For SA LTE-U system, we design a novel random access protocol, and propose an algorithm to calculate the optimal number of Random Access Channels (RACHs) which balances the resources between RACHs and Uplink Shared Channels (UL-SCHs). Specifically, we formulate an optimization...
The paper presents a real-time operating system (RTOS) that supports location-transparent shared resource management and distributed shared memory for distributed embedded control systems with CAN (Control Area Network) buses. In a distributed embedded control system, location-transparent mechanisms are required because application tasks are distributed to a number of nodes. We have developed a RTOS...
In the near future, it is expected that a large number of machine-to-machine (M2M) communication devices will provide with ubiquitous information and services. Random access protocols like ALOHA ans CSMA have been considered for M2M networks for their simplicity of operation. This paper evaluates the performance of a Frame Slotted-ALOHA protocol that deploys reservation and data packets (FSA-RDP),...
The challenging performance targets of future 5G networks will require a radical change in the network design with a much closer interaction between wireless and optical systems. Dynamically reconfigurable time-division multiplexing (TDM) dense wavelength division multiplexing (DWDM) long-reach passive optical networks (PONs) provide a promising platform to enable the convergence of residential broadband,...
In this paper, we improve throughput performance of a cognitive radio network through a proposed dual-level sensing strategy. Throughput performance of secondary users cannot be enhanced while providing higher priority to protect primary users from secondary user interference. Therefore, we propose a novel multiple access scheme based on dual-level sensing strategy by which both the interference protection...
The convergence of multiple service demands and different user types on a single physical layer can be enabled by dynamically reconfigurable time-division multiplexing (TDM) dense wavelength division multiplexing (DWDM) long-reach passive optical networks (PONs). In this paper we demonstrate two TDM-DWDM PON designs, the first one for densely populated urban areas and the second one better suited...
We study the optimum designs of a wireless ad hoc network that employs a random multiple access protocol and operates in an interference-limited environment. The nodes are assumed to form a homogeneous Poisson point process (PPP). With the random multiple access protocol, each node transmits with a certain probability, the value of which is critical to system performance. A higher transmission probability...
We present a connection establishment protocol with integrated authentication, suited for Massive Machine-Type Communications (mMTC). The protocol is contention-based and its main feature is that a device contends with a unique signature that also enables the authentication of the device towards the network. The signatures are inspired by Bloom filters and are created based on the output of the MILENAGE...
Data accountability can record and track data usage in cloud storage, in order to cope with users' fear of losing control of their own data or even data leakage. However, logs recording unauthorized data access could be omitted or falsified in untrusted cloud storage, which is the critical factor of unreliable data accountability. To address this problem, in this paper, we propose a novel Cloud Data...
We propose graph-defined IRSA (G-IRSA), a new approach to design irregular repetition slotted ALOHA (IRSA) uncoordinated multiple access schemes for a controlled-size population of users that become active sporadically. The proposed scheme considers a joint design of the distribution according to which users select their repetition factors and the distribution determining how many packet replicas...
This paper proposes a new model for data access and sharing within a spatial data infrastructure. Spatial data infrastructure, often proposed at national level, refers to the enabling of wider access to geographical data so that better knowledge can be generated to promote social, environmental and economic benefits. A good spatial data infrastructure includes people, policies, tools, methods and...
It has been well-known that slotted ALOHA systems exhibit unfavorable bistable behavior, since 1970s. It was proved that we can eliminate bistable region by limiting the number of allowable transmission attempts per packet to eight or less. In this paper, we investigate bistable behavior of slotted ALOHA systems with delay constraints and geometric transmission probability in terms of the catastrophe...
This article is devoted to the effectiveness of security systems using Honeypot technology. There are studied basic structures of security systems, which use Honeypot technology. There is described developing process of a “trap” for VNC/RDP protocols, which main goal is to emulate remote desktops. Assembled “trap” will identify the attacker to collect information about his actions by analyzing malicious...
We present a random access method inspired on Bloom filters that is suited for Machine-Type Communications (MTC). Each accessing device sends a signature during the contention process. A signature is constructed using the Bloom filtering method and contains information on the device identity and the connection establishment cause. We instantiate the proposed method over the current LTE-A access protocol...
Decentralized cognitive radio networks (CRN) require efficient channel access protocols to enable cognitive secondary users (SUs) to access the primary channels in an opportunistic way Without any coordination. In this paper, we develop a distributed spectrum access protocol for the case where the SUs aim to maximize the total system throughput while competing for spectrum resources. To model the...
In the buoy satellite communications system based on LEO satellite access, to improve channel utilization under different traffic load situation, a novel competitive access protocol named FC-TDMA (Fixed Competitive TDMA) is proposed in this paper. The protocol takes advantage of both TDMA and S-ALOHA, allocates unique user ID for every node, and adjusts transmission rate according to network load,...
Machine-to-Machine (M2M) communications are expected to be one of the major drivers of future cellular networks, due to a plethora of services provided to operators and consumers. This leads to an explosively growth of simultaneous M2M arrivals, and then a bursty random access attempts that causes a severe random access congestion in addition to terminals' synchronization issues. In this paper, we...
In this paper we treat the problem of identification of a subset of active users in a set of a large number of potentially active users. The users from the subset are activated randomly, such that the access point (AP) does not know the subset or its size a priori. The active users are contending to report their activity to the AP over a multiple access channel. We devise a contention algorithm that...
The neighbor discovery (ND) procedure is typically performed during the network setup and allows nodes to learn about the existence of neighbors, exploiting the transmission of broadcast messages. Battery powered nodes impose many constraints on the ND protocol, such as low latency and energy efficiency. This calls for the deployment of dedicated and efficient ND protocols allowing nodes to be idle...
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