Spatial Big Data and Moving Objects: A Comprehensive Survey <s> B. ROUTING ALGORITHMS FOR MODERN DAY BIG DATA NETWORKS <s> In mobile ad-hoc cognitive radio networks (CRNs), end-to-end paths with available spectrum bands for secondary users may exist temporarily, or may never exist, due to the dynamism of the primary user activities. Traditional CRN routing algorithms, which typically ignore the intermittent connectivity of network topology, and traditional mobility-assisted routing algorithms, which generally overlook the spectrum availability, are obviously unsuitable. To tackle this challenge, we propose a Mobility-Assisted Routing algorithm with Spectrum Awareness (MARSA) to select relays based on not only the probability that a node meets the destination but also the chance at which there exists at least one available channel when they meet. To the best of our knowledge, this paper is the first to bring the idea of mobility-assisted routing to deal with the intermittently connected attribute of mobile ad-hoc CRNs, and the first to enhance the mobility-assisted routing by considering the temporal , spatial, and spectrum domains at the same time. Our simulation results demonstrate the superiority of MARSA over traditional algorithms in intermittently connected mobile CRNs. <s> BIB001 </s> Spatial Big Data and Moving Objects: A Comprehensive Survey <s> B. ROUTING ALGORITHMS FOR MODERN DAY BIG DATA NETWORKS <s> In D2D communications, random contacts can be utilized to exchange data among nodes without the support from infrastructures or central control units. Because of the huge quantity and high mobility of the nodes, the scarcity of the available spectrum severely limits the data delivery capacity in D2D communications. CR technology gives D2D the ability to use idle licensed radio spectra from licensed networks to improve data delivery capacity. The advantages of opportunistic data delivery and CR technology make D2D communications an alternative that provides a complementary technology for big data applications. However, efficient routing algorithm design in D2D communications with CRD2D is nontrivial due to the spatial, temporal, and spectrum limitations introduced by node mobility and the available spectrum bands. This article investigates and analyzes the latest routing algorithms for D2D communications and CR networks. Taking advantage of the integration of D2D and CR techniques, a routing framework with social awareness for big data applications is proposed, which employs the regularities of nodes' mobility and spectrum mobility to improve the performance of data delivery. Open research issues for big data routing in CRD2D networks are also addressed. <s> BIB002 </s> Spatial Big Data and Moving Objects: A Comprehensive Survey <s> B. ROUTING ALGORITHMS FOR MODERN DAY BIG DATA NETWORKS <s> Device-to-device (D2D) communication presents a new paradigm in mobile networking to facilitate data exchange between physically proximate devices. The development of D2D is driven by mobile operators to harvest short range communications for improving network performance and supporting proximity-based services. In this paper, we investigate two fundamental and interrelated aspects of D2D communication, security and privacy, which are essential for the adoption and deployment of D2D. We present an extensive review of the state-of-the-art solutions for enhancing security and privacy in D2D communication. By summarizing the challenges, requirements, and features of different proposals, we identify lessons to be learned from existing studies and derive a set of “best practices.” The primary goal of our work is to equip researchers and developers with a better understanding of the underlying problems and the potential solutions for D2D security and privacy. To inspire follow-up research, we identify open problems and highlight future directions with regard to system and communication design. To the best of our knowledge, this is the first comprehensive review to address the fundamental security and privacy issues in D2D communication. <s> BIB003 </s> Spatial Big Data and Moving Objects: A Comprehensive Survey <s> B. ROUTING ALGORITHMS FOR MODERN DAY BIG DATA NETWORKS <s> Spectrum handoff plays an important role in spectrum management as it is the process of seamlessly shifting the on-going transmission of a secondary user (SU) to a free channel without degrading the quality of service. In this paper, we develop an adaptive handoff algorithm that allows an SU to detect the arrival of a primary user (via sensing) and adapt to a reactive or a proactive handoff strategy accordingly. The adaptive handoff scheme first allows an SU to decide whether to stay and wait on current channel or to perform handoff. Then, in case of handoff, an SU intelligently shifts between proactive or reactive handoff modes based on primary use (PU) arrival rate. Further, a PU prioritized Markov approach is presented in order to model the interactions between PUs and SUs for smooth channel access. Numerical results show that the proposed handoff scheme minimizes the blocking probability, number of handoffs, handoff delay and data delivery time while maintaining channel utilization and system throughput at maximal level compared to simple reactive and proactive schemes. <s> BIB004
Here we consider routing algorithms designed for BD traffic generated in modern day networks. We focus on various types of networks such as cognitive radio (CR) networks, D2D communications, SDN, energy efficient networks, MANETs (mobile ad hoc networks) and so on. The work cited in this section is not limited to the aforementioned types of networks and can easily be adapted to all kinds of traditional wireless networks. Our classification for this section is summarized in figure 4. BIB002 D2D communication BIB003 plays an important role in BD networks due to its ad-hoc nature, flexible and light weight architectures, and anytime availability especially in critical conditions where the network resources are merely available. Huang et al. BIB002 address this interesting concept combining D2D communications with cognitive radio (CR) technology that exploits the unused licensed and unlicensed freely available spectrum BIB004 . This work falls within the scope of our survey since the devices movement is related to the movement of a person from one geographical location to another and thus, the routing algorithm is proposed based on real-time mobility of people. Basically, by integrating D2D and CR technologies, a ''socially aware'' big data (greedy) routing algorithm is proposed which uses the mobility of devices and spectrum as benefits for efficient data delivery. Here the mobility of nodes refers to the movement of people from one location to another which is finite and follows a periodic pattern. Same trend applies to the mobility of spectrum which is based on daily activities of licensed or primary users and thus can be predicted having finite patterns. In the proposed ''greedy'' algorithm, a node 'x' chooses the most optimal node in the neighborhood which then acts as a ''relay'' to forward the data of 'x'. This optimal selection and relaying process continues unless the data reaches its final destination. Besides the proposed algorithm, the authors describe in detail the concept of CRD2D networks and identify open issues related to routing in these networks (such as effects of weak links on delivery of data, nodes communication overhead, and traffic control) which remained untouched in BIB001 .