Implementation-level benchmark of ETSI GS QKD 004 and ETSI GS QKD 014 key-delivery interfaces in NS-3/QKDNetSim

Mobile ad hoc networks shows unexpected behavior with multiple data streams under heavy traffic load such as multimedia data when it is sent to common destination. The main reason for packet loss in mobile ad hoc networks is due to congestion. In the current design, the routing protocols are not congestion adaptive. The way in which the congestion is handled results in longer delay and more packet loss. When a new route is needed the routing protocols take significant overhead in finding it. In this paper we propose an adaptive congestion control algorithm, which out-performs even during constrained situation. For analyzing the performance we have chosen four popular routing protocols such as AODV, DSR, DSDV and TORA. We also observe through simulation in NS-2 that AODV outperforms other routing protocols in normal situation and DSR out-performs in constraint environment. The proposed congestion control routing protocol outperforms all the other routing protocols during heavy traffic loads. We strongly argue that routing should not only be aware of but also be adaptive to network congestion

In location management services, a destination advertises its position attributes to a set of vehicles called location servers while, a source obtains these attributes from such location servers to track destination. The location management techniques in VANET have been categorized into flooding-based, flat hashing-based, hierarchical hashing-based and hierarchical quorum-based techniques. In flooding-based location service, destination information is flooded to the entire network which results into high congestion, low throughput and non-scalable network. In flat hashing, a global hash function is applied to compute location servers of each destination which results into higher delay, drop and signaling overhead in large VANETs. In hierarchical hashing, global hash function computes location servers of destination in hierarchical order. It therefore suffers from handover signaling between servers, high load on the top hierarchy and location query delay when source and destination are apart. In hierarchical quorum-based, location servers are identified cluster-wise and therefore it also suffers from the problems similar to hierarchical techniques. To overcome these problems, ZoomOut Geographic Location Service (ZGLS) protocol is proposed which introduces flat quorum-based location management service. In contrast to the aforementioned techniques, the novelty of ZGLS lies in the fact that it has shifted the location server role from hashing-based or clustering-based geographic areas to few 1-hop neighbours, called relatives. The proposed protocol creates a chain of relatives to provide positioning and tracking service. To evaluate signalling overhead, timeliness and the reliability of update and query packets, ZGLS is compared with RLSMP and HRHLS through ns-2 simulations. The results reveal that ZGLS stands out as a better choice for large-scale sparse and dense VANETs.

The IEEE 802.15.3 MAC enables high-rate communications between devices in a wireless personal area network and has good support for applications requiring quality of service (QoS). To meet applications' QoS requirements, such as delay and jitter, the channel time allocation (CTA) scheduler plays an important role in sizing and positioning CTAs within each super-frame. In this paper, we first present a novel CTA sharing protocol, called VBR-MCTA that enables the sharing of CTAs belonging to streams with the same group identity. This allows our protocol to exploit the statistical characteristics of variable bit rate (VBR) streams by giving unused time units to a How that requires peak rate allocation. We then present two optimizations to VBR-MCTA, namely VBR-Blind and VBR-TokenBus. The former, by giving ownership of a CTA in a round-robin manner without consideration to traffic profiles, does not consume any valuable air-time with signaling overheads. The latter allows a CTA to be shared by multiple devices that take turns owning unused air-time from CTAs. We have simulated VBR-MCTA and its optimizations in the ns-2 simulator over an implementation of the IEEE 802.15.3 MAC. Our results show that VBR-TokenBus has the best delay and jitter as it provides a one to six milliseconds reduction in both compared to standard CTA methods. VSR-Blind, although having performing poorer than MCTA-Token or VBR-MCTA, is still significantly better than traditional CTA methods at a reduced overhead.

Efficient hierarchical SIP mobility management for WiMAX networks

In this paper, we propose a greedy framework for distributed scheduling in the IEEE 802.16 MeSH mode, which uses a novel “End-to-end QoS aware bandwidth Reservation Protocol” (EQRP) to provide end-to-end QoS guarantee to intramesh flows. The proposed framework provides an efficient and integrated solution to QoS aware routing and call admission control in distributed WiMAX mesh networks. The framework does not rely on any special node for resource management which makes it more scalable and robust to node failures. To save expensive control overheads, EQRP learns from previous bandwidth reservation failures to maintain a rank list of next hops for every destination and uses the “Greedy Forwarding” algorithm to do bandwidth reservation using slot information from only two hop neighbor routers'. We compare EQRP with Race Free Protocol (RFP) and evaluate its performance with extensive simulations in ns2. Simulations show that for static WiMAX mesh network, the “Greedy Forwarding” algorithm used by EQRP admits approximately 10% more VOIP calls. For a random topology of 25 mesh routers, the aggregate signaling overhead generated by EQRP at a high call arrival rate of 1/2000 (calls/milli-seconds) is 76% less than that generated by RFP. In comparison with RFP, EQRP took 200 milli-seconds less average call setup time.

Cryptographic algorithms enable secure data communication over public insecure networks. Though they enhance network security, complex cryptographic operations consume substantial amounts of computing resources, introducing significant network overhead costs. This study aims to find the cryptographic algorithm that can efficiently utilize network resources. The study evaluates three cryptographic algorithms with different file formats on varying numbers of node densities. The NS-3 simulator was used to measure latency, data throughput, end-to-end delay, packet delivery ratio, and packet loss of files in text, image, and audio formats. The results find AES as better than DES and 3DES for a large number of node densities for the three file formats in terms of latency, data throughput, end-to-end delay, and packet delivery ratio. However, DES has the lowest packet loss as AES records the highest packet loss. The findings provide researchers avenues for further research and the practitioners the choice of suitable algorithms based on the overhead performance.

In recent years, there has been a tremendous increase in the cellular traffic due to the availability of wide range of devices: smart phones, net-books, tablets, etc. The existing cellular networks will be unable to cater to the increasing demands in near future, thus we need technological enhancements in the cellular infrastructure to meet the ever increasing user requirements. Various approaches have been suggested to increase the existing cellular capacity and provide higher data rates, some of which include deployment of small cells under the coverage area of Macro cells, where a cell denotes the region covered by a particular base station (BS). However, since these small cells cover small regions there exists a significant handover signalling overhead. We suggest an approach where small cells, called Phantom cells, are deployed within the Macro cell coverage area, and the existing Macro BS functions as the centralized controller for all the Phantom BSs deployed within its range. Phantom BSs act as a supplement to the existing Radio Access Network in the LTE infrastructure where it handles the data plane (D-plane) and Macro BSs handle the control plane (C-plane). This paper proposes the definitions of Copiane and D-plane, the modifications in the user equipment (UE) protocol stack which enable the concurrent operation with dual BSs (Phantom and Macro). Mechanisms are developed for the communication of a Phantom BS with a Macro BS over the new interface (X3 interface). NS-3 simulations were performed incorporating the designed architecture for Phantom based HetNets and a significant improvement in UE throughput is observed in comparision with legacy networks comprising of Macro BS.

This paper analyzes and evaluates the Distributed Node Consensus Protocol (DNCP), a state synchronization mechanism developed by the IETF Homenet working group. DNCP enables network function automation for home networks, which are growing in size and complexity. The basic mechanisms of DNCP are studied in this paper, including the state abstraction, synchronization process and keep-alive mechanism. The overhead is analyzed in single-link topology type. To evaluate the performance of DNCP in more complex scenarios, a reference implementation of DNCP is integrated into ns3 simulator. The convergence time and transmission overhead in various topology types are measured. Based on the obtained results, the correctness of DNCP is verified, and the behavior of DNCP can be concluded.

Clustering schemes offer a practical way of providing scalability when dealing with large and dense Mobile Ad hoc Networks (MANETs). The feasibility of clustering can be determined by the complexity of the cluster head selection. Optimizing the cluster head selection allows for the network to be more efficient by minimizing the signaling overhead while ensuring that the network connectivity is maintained despite topology changes. In this paper, we present some new findings on the complexity of the cluster head selection algorithms. Two variants of the cluster head selection are examined: (1) the distance-constrained selection where every node in the network must be located within a certain distance to the nearest cluster head; and (2) the size-constrained selection where each cluster is only allowed to have a limited number of members. We show that the problem of minimizing the set of cluster heads is NP-hard for both variants. We propose two distributed selection algorithms, each having logarithmic approximation ratio, for these variants. We also discuss, using NS-2 simulations, the resulting cluster size distribution and cluster head density, which impact the efficient operation of the network.

In this work, we focus on increasing network utilization to support real-time applications, especially voice over IP, in 802.11b wireless mesh network. For increasing capacity, we investigate on two directions: use of packet aggregation and utilize of header compression. Although aggregation reduces 802.11 MAC overhead, it also increases delay. We present a distributed multihop aggregation algorithm that uses the "natural" waiting time in the interface queue of packets in a loaded network. Header compression can relax the VoIP protocol overhead, but it also introduces the signaling overhead. In our work, we propose a zero-length header compression algorithm integrated with packet aggregation, which doesn't need to depend on the signaling mechanism to recover the context discrepancy between compressor and decompressor. The above performance optimization techniques are experimented in the NS2 simulator. The experimental results show an increase of 12 times for a six hop string when all optimizations are used

The recent development of various wireless technologies in the 2.4GHz ISM band has led to the co-channel coexistence of heterogeneous wireless devices, such as Wi-Fi, Bluetooth, and ZigBee. This sharing of the common channel results in the challenging problem of cross-technology interference, since the wireless devices generally use diverse PHY/MAC specifications. In particular, the less capable ZigBee device may often experience unpredictably low throughput due to the interference from the powerful Wi-Fi. The ZigBee protector is an attractive solution, since it can reserve the channel on behalf of the weak ZigBee devices. The protector method, however, has a few limitations; (i) it may cause significant overhead to both ZigBee and Wi-Fi, and (ii) the ZigBee control packets are still vulnerable to the Wi-Fi interference. In this paper, we propose a novel time reservation scheme called Narrow Band Protection (NBP), that uses a protector to guard the ongoing ZigBee transmission. The key contributions are threefold: First, NBP autonomously detects any ongoing ZigBee transmissions by cross-correlating the ZigBee’s packets with the pre-defined Pseudo-random Noise (PN) sequences. By using this cross-correlation, it significantly reduces the control overhead. Second, due to the reliable cross-correlation, NBP is robust from the control packet collisions, which typically wastes channel time for both ZigBee and Wi-Fi. Third, NBP protects the burst of ZigBee packets by estimating the size of the burst, in turn, giving a semantic to the PN codebook. This is important because ZigBee is typically battery-powered and thus the long burst is advantageous for the low duty cycle operations. We first show the feasibility of NBP by implementing it on the real USRP/GNURadio platform. Then, we evaluate the performance of NBP through mathematical analysis and NS-2 simulations. The results show that NBP enhances the ZigBee throughput by up to 1.77x compared to the existing scheme.

This research focuses on developing a velocity-based routing (VELOR) protocol for city and urban vehicular ad hoc networks. VELOR is a two-level routing protocol. The first level finds the intersections to be traversed along the routing path based on the road topology and vehicular traffic on each road segment. Selective flooding method is developed to reduce congestion and signaling overhead. At the second level, forwarding optimization is carried out using the standby function for selecting next-hop node based on the identified parameters. These parameters are the farthest predicted neighbor and the transmission probability. Simulations performed using Simulation of Urban Mobility (SUMO), BonnMotion and NS-2 compare the AODV, OLSR, GPSR and GOSR routing protocols with VELOR. VELOR shows as much as 35% increase in average packet delivery ratio and as much as 50% decrease in the average end-to-end delay as compared to the other protocols in high density, urban networks. On comparing across various mobility scenarios, the packet delivery ratios for all the protocols drop significantly with the increase in mobility model complexity, except for VELOR which is stable throughout. Across all the mobility models, the delays increase for all other protocols with increasing node density. However, for VELOR, the delay decreases.

The mobility management architecture in current generation LTE networks results in high signaling traffic. In this chapter, we present an Evolved Packet Core (EPC) architecture based on Software Defined Networking (SDN) concepts. The proposed EPC architecture centralizes the control plane functionality of the EPC thereby eliminating the use of mobility management protocols and reducing mobility related signaling overheads. The architecture utilizes the global network knowledge with SDN for mobility management. The proposed architecture has been implemented in the ns-3 simulator. A prototype testbed has also been implemented using the Floodlight SDN controller, a Software Defined Radio platform and relevant software.

Several Information Centric Network (ICN) architectures have been proposed as candidates for the future Internet, aiming to solve several salient problems in the current IP-based Internet architecture such as mobility, content dissemination and multi-path forwarding. In general, security and privacy are considered as essential requirements in ICN. However, existing ICN designs lack built-in privacy protection for content providers (CPs), e.g., any router in an Internet Service Provider in ICN can cache any content, which may result in information leakage. In this paper, we propose Mandatory Content Access Control (MCAC), a distributed information flow control mechanism to enable a content provider to control which network nodes can cache its contents. In MCAC, a CP defines different security labels for different contents, and content routers check these labels to decide if a content object should be cached. To ensure correct enforcement of MCAC, we also propose a design of a trusted architecture by extending existing mainstream router architectures. We evaluate the performance of MCAC in the NS-3 simulator. The simulation results show that enforcing MCAC in routers does not introduce significant overhead in content forwarding.

Future cellular networks will be dense and require key traffic management technologies for fine-grained network control. The problem gets more complicated in the presence of different network segments with bottleneck links limiting the desired quality of service (QoS) delivery to the last mile user. In this work, we first design a framework for software-defined cellular networks (SDCN) and then propose new mechanisms for management of QoS and non-QoS users traffic considering both access and backhaul networks, jointly. The overall SDN-LTE system and related approaches are developed and tested using network simulator (ns-3) in different network environments. Especially, when the users are non-uniformly distributed, the results shows that compared to other approaches, the proposed load distribution algorithm enables at least 6\% and 23\% increase in the average QoS user downlink (DL) throughput for all network users and 40\%-ile edge users, respectively. Also, the proposed system efficiently achieves desired QoS and handles the network congestion without incurring significant overhead.