Location Management Scheme Research Articles

A secure location management scheme in an LEO-satellite network with dual-mobility

A secure location management scheme in an LEO-satellite network with dual-mobility

A Location Management Strategy for Satellite Internet Constellation

Satellites are currently the most effective means to achieve seamless global coverage of the Internet. Due to the frequent beam switching caused by the high-speed movement of satellites, it is too expensive to directly apply the location management strategy in the terrestrial network to the satellite Internet constellation (SIC). To build a web browsing platform based on satellite Internet, it is necessary to display the location of satellites and terminals in real time. For this reason, this paper proposes the location management strategy of SIC. It uses the characteristics of large and periodic satellite beam coverage in a certain period of time, redesigns the location management database structure, location registration mechanism and call delivery mechanism, and analyses and simulates the bit cost of location management. The result proves that compared with the traditional strategy, this strategy greatly reduces the cost of SIC.

Evaluation and Application of New-Semarang Coastal Resources Management

The beach in Semarang’s city has a variety of uniqueness with a variety of types and potential. The beach located on the north coast of Semarang city has various characteristics and strengths, and weaknesses. In overcoming differences in management and avoiding misunderstandings between governments, it prioritizes managing the coastal location. At least four integrated coastal management sub-systems consist of Human Resources Management, Accessibility, Beach Location Infrastructure, and Management Policies. This research was conducted from April 2020 until August 2020, to determine the most appropriate alternative strategy to be chosen and implemented in coastal location management. Study analysis with an Analytical Hierarchy Process-AHP analytical technique use with Application R - Open sources. The integrated coastal area management can as the most appropriate coastal location management strategy to implement the current situation and future planning. Alternative methods planned for use are the Availability of a Security Guard, Ease of Access with Signage, Parking Lots, and Rule or regulations to an Integrated Location. The study results stated that the best strategy is management collaboration in the form of interrelated rules.

Location of temporary buildings at LNG site based on quantitative studies

AbstractTemporary buildings, installed on site during the construction phase, may not be removed until the commissioning, completion, or beginning of normal operation. Once the hydrocarbons are introduced, these buildings have the potential to be exposed to process hazards (fire, explosion, toxicity, etc.) resulting in injury or fatality of the personnel inside the building. Providing safe location to these portable building is imperative and should be determined based on detailed hazard analysis, building siting study as per API 753. Facility siting study is done to calculate the potential impact of blast overpressure, thermal radiation from jet fires, pool fires, and toxicity hazards and evaluate the safe distance to the temporary buildings. Simultaneous operations is also evaluated in order to optimize temporary building location and further risk management strategies are implemented such as mitigation measures based on the hazard impacts, like, adding gas detectors at the air intake of HVAC to shut down the power supply to the temporary buildings, public announcement system, evacuation drills, and so on. This paper will address the temporary building siting study and associated mitigation measures with the highlight of its application into the risk management, using a large LNG facility as an example.

Surgical techniques in the management of supratentorial pediatric brain tumors: 10 years' experience at a tertiary care center in the Middle East.

Background: The goal of this retrospective study is to present the first epidemiological data on pediatric supratentorial central nervous system (CNS) tumors in Lebanon and to review the various surgical management strategies used.Methods: We conducted a retrospective case series of all pediatric patients who presented with a supratentorial CNS tumor and underwent surgery at our institution between 2006 and 2016. We collected and analyzed demographic characteristics, tumor location, clinical manifestations, histopathology, and surgical management strategies and outcome, and discussed them after dividing the tumors as per location and in view of published literature.Results: Ninety-nine children were studied with a male-to-female ratio of 2.3:1 and a mean age of 8.5 years. The most common location was convexity (44%) and included low-grade and high-grade glial tumors, along with other miscellaneous lesions. The next location was sellar/diencephalic (34%), including craniopharyngiomas, hypothalamic/optic pathway/thalamic gliomas, hamartomas, and pituitary/Rathke’s cyst, where there was notable use of endoscopic techniques (21%). Tumors in the pineal region (13%) were tectal gliomas, germ cell tumors, and pineoblastomas and were mostly treated endoscopically. The last group was lateral intraventricular tumors (8%) and was mostly choroid plexus lesions and ependymomas. Overall, the surgical objective was achieved in 95% with mild/moderate complications in 17%.Conclusion: A variety of pathologies may affect the pediatric population in the supratentorial region. Different surgical strategies, including microsurgical and endoscopic techniques, may be employed to remove, debulk, or biopsy these tumors depending on their location, suspected diagnosis, prognosis, and the need for treatment of possible associated hydrocephalus.

Examining the Impact of E-Commerce Growth on the Spatial Distribution of Fashion and Beauty Stores in Seoul

E-commerce has dramatically expanded its sales, with people being increasingly customed to online shopping. This study aimed to examine changes in the distribution of retail stores that provide fashion and beauty products and services in terms of the number of online shopping transactions and their spatial characteristics in Seoul. For this purpose, we analyzed location data concerning relevant newly opened and closed offline stores from four subgroups between 2015 and 2019. Though more offline stores were newly opened than closed in that period, the number of stores had overall significantly decreased apart from stores providing beauty services, with significant differences in subgroup spatial distribution patterns. We identified local geographic factors affecting retail stores by applying spatial regression models, and we found that the growth of e-commerce was associated with the related to the survival and closure of fashion and beauty stores. While retail store locations are not immediately responsive to changes due to COVID-19, we expect the prolonged COVID-19 outbreak will further facilitate the spatial transformation that has been stimulated by rise of online retailing. Our findings provide important basic data for establishing location plans and management strategies for future fashion and beauty stores, as well as timely evidence-based data to help direct subsequent academic research.

CBLM: Cluster-Based Location Management for 5G Small Cell Network Under Stochastic Environment

Internet of Things (IoT) applications are connecting several Mobile Stations (MSs) to form the Mobile Communication Network (MCN). MSs are moving through macrocell and picocell recurrently due to the discontinuous deployment of the picocell over the macrocell. Each time they cross the cell boundary, they need to register with the Mobility Management Entity (MME). It incurs a high registration cost and elevates the signaling overhead ratio. To reduce the signaling overhead ratio, earlier techniques were attempted either by forming closed subscriber groups or by delaying the registration process, but that may create inconsistency in user location information. With this motivation, in this paper, MSs with similar mobility pattern which are moving from the picocell to macrocell, are grouped in clusters. A representative MS, called Cluster Representative (CR), performs the location management task on behalf of the whole cluster. The stochastic process has been employed to analyze the model. This study proposes Cluster-Based Location Management (CBLM) scheme and compares it with two state-of-the-art algorithms, named Group Mobility Management (GMM) and Closed Subscriber Group (CSG). On average, the CBLM scheme exhibits approximately 70% better performance than the CSG scheme whereas, 30% better than the GMM algorithm to mitigate the signaling overhead.

ADVICE-LOC: An adaptive vehicle-centric location management scheme for intelligent connected cars

With the recent advances and wide availability of heterogeneous wireless access technologies, inter-vehicle communication systems are expected to culminate in the integration of different wireless networks based on such standards as 5G/6G, coupling with multimedia and sensor networks for the next generation of connected and autonomous vehicles. However, the high mobility nature of vehicles poses intrinsic research challenges on the mobility management and the integration of different wireless technologies. Towards this end, in this paper, we propose an ADaptive VehIcle-CEntric LOCation management protocol (ADVICE-LOC) that utilizes the individual mobility projection of each vehicle and estimates the vehicles’ residual time within each access point. Its ultimate objective is to eliminate the network communication’s overhead, while guaranteeing a high packet delivery ratio and low latency rates. The proposed protocol preemptively adjusts the vehicles’ access registration and location updates based on its movement projections. We present our protocol, and we report on its performance evaluation using an extensive set of experiments using SUMO generated vehicles’ mobility. Our results indicate that the proposed DEVICE-LOC protocol succeed significantly in reducing the communication overhead while sustaining high packet delivery ratio when compared to previous studies.

Surgical approaches in pediatric neuro-oncology.

Tumors of the central nervous system comprise nearly a quarter of all childhood cancers and are the most frequent solid tumor in the pediatric population. The most common location is in the posterior fossa, but tumors can occur anywhere intracranially. The spectrum of lesions encountered varies, from being completely benign and requiring surveillance alone to being highly malignant and requiring aggressive treatment in the form of surgery and adjuvant therapy. The extent of resection plays a crucial role in the oncological outcome of many of these tumors. A variety of surgical approaches are available for the spectrum of lesions encountered. This review focuses on summarizing the location, types, and neurosurgical management strategies for pediatric brain intracranial brain tumors. Here, we discuss neurosurgical approaches for a variety of brain tumors and regions, including the management of tumors of the posterior fossa, brainstem, pineal region, intraventricular region, sellar and suprasellar regions, optic pathway and hypothalamus, and supratentorial hemispheres.

Artificial immune system (AIS)-based location management scheme in mobile cellular networks

In this paper, we are proposing a bio-inspired location management (LM) technique for personal communication system (PSC). It is based on artificial immune system (AIS), with self-adaptation and self-update attributes to perform the location management, and helps to achieve better quality of service (QoS) and quality of experience (QoE) for the mobile users. Here, we are suggesting a modified mobile switching center (MSC) architecture, and an adaptive self-modified location management procedure. The proposed mobile switching center architecture has an advantage of rule-based and fact-based system to store the rules and facts related to location management procedure, and it shows the intelligent behavior of system. The mobile switching center calculates the best method for location management and the rule-based system trigged the rules to perform the techniques. The system stores the result (techniques for location management) in fact-based system for future use. The efficiency and effectiveness of the proposed techniques have been analyzed, and it observed that the proposed system has 45–50% improvement in performance over the current location management techniques. Here, we are using performance parameters such as signaling cost, database update cost, overhead measurement, and mobility management cost.

MALM: Mobility-Aware Location Management Scheme in Femto/Macrocell Networks

Recently, femtocells are widely deployed to offload the traffic from the macrocell. Since conventional location management schemes of femto/macrocell networks do not consider mobility pattern of the mobile node (MN), unnecessary location updates can occur. Specifically, when an MN moves along the contour of the femtocell coverage, the MN frequently executes location update procedures, which causes significant location update cost. To address this problem, we propose a mobility-aware location management (MALM) scheme, where the MN conducts location update only at specific femtocells in which it is expected that the MN stays for a long time. To optimize MALM, a Markov decision process (MDP) problem is formulated and the optimal policy is determined. Evaluation results demonstrate that MALM with the optimal policy can reduce the number of location updates while providing sufficient offloading gain.

Cluster-Based Mobile Sink Location Management Scheme for Solar-Powered Wireless Sensor Networks

Cluster-Based Mobile Sink Location Management Scheme for Solar-Powered Wireless Sensor Networks

DLM: Delayed location management in network mobility (NEMO)-based public transportation systems

Network mobility basic support (NEMO-BS) supports efficient group mobility. However, when NEMO-BS is applied to public transportation systems where mobile nodes (MNs) frequently get in/off the public transportation, significant signaling overhead owing to frequent and unnecessary binding updates can occur. To address this problem, we propose a delayed location management (DLM) scheme where an MN postpones its binding update for a pre-defined timer to mitigate the binding update overhead. To evaluate the performance of DLM, we develop an analytical model for the binding update cost and the packet delivery cost during the boarding time. Also, a timer selection algorithm is proposed to optimize the performance of DLM. Evaluation results demonstrate that DLM can reduce the binding update cost and packet delivery cost in a balanced manner by choosing an appropriate timer.

A dynamic location management service for group applications in cellular networks

Mobile telephony is rapidly evolving with new services, and one-to-many group applications, such as Push to Talk over Cellular services, are expected to be more prevalent in the near future. The core issue that needs to be addressed in order for such services to be practical on a large scale is efficiency. Cellular providers are virtualizing network functions to introduce services in an agile and cost effective manner. Location management is a key control task in cellular network operations. We propose and develop an efficient group location management scheme as a virtualized network function for group cellular applications. The performance improvement is mainly achieved by the virtualized and separate group management architecture and an efficient dynamic group profiling algorithm. We conduct theoretical analyses of our scheme for signaling cost and performance gains under diverse traffic conditions. Furthermore, we carry out extensive evaluations using both real traces and synthetic human mobility data, and we validate the efficiency of the proposed scheme in both location updates and paging.

Location distribution of a mobile terminal and its application to paging cost reduction and minimization

Reducing the cost of dynamic mobility management in wireless communication networks has been an interesting and important issue. It is well known that by using a selective paging method, both costs for location update and terminal paging can be reduced significantly. However, an efficient selective paging method needs the information of the location distribution of a mobile terminal. Based on our previous results on random walks among rings of cell structures, we analyze the location distribution of a mobile terminal in a paging area when a phone call arrives, where the inter-call time and the cell residence time can have arbitrary probability distributions. Our analysis is conducted for both distance-based and movement-based location management schemes, and for two different call handling models, i.e., the call plus location update model and the call without location update model. Together with our earlier results on location distribution in time-based location management schemes, for several selective paging methods, including progressive paging methods, ring paging methods, and cell paging methods, we are able to obtain their expected costs of paging for distance-based, movement-based, and time-based location management schemes. We find that a progressive paging method with very small time delay can reduce the terminal paging cost dramatically, while further increasing the time delay does not result in noticeable reduction of terminal paging cost. Our work reported in this paper significantly extends our understanding of cost reduction and minimization of dynamic location management in wireless communication networks.

Modeling and Performance Analysis of a Tracking-Area-List-Based Location Management Scheme in LTE Networks

In a cellular network, the network coverage is partitioned into nonoverlapping areas called registration areas to facilitate location management (LM) that keeps track of the location of a user equipment (UE) unit. In the second-generation Global System for Mobile Communications (GSM) and the third-generation Universal Mobile Telecommunications System (UMTS), a registration area is called a location area (LA) in the circuit-switched domain or a routing area (RA) in the packet-switched domain. In the fourth-generation Long-Term Evolution (LTE), a registration area is called a tracking area (TA). To tackle the drawbacks of the LA/RA-based LM scheme used in GSM and UMTS, which is intrinsically a static scheme, LTE adopts a dynamic LM scheme called a TA list (TAL)-based scheme. Under the TAL-based scheme, the network allocates to a UE unit a group of TAs referred to as a TAL instead of only a single TA. The UE can move freely within the allocated TAL without performing any location updates that are called TA updates (TAUs) in LTE. Only when moving into a TA that is not included in the allocated TAL does the UE need to perform a TAU, and afterward, the network will allocate, to the UE, a new TAL. The performance of the TAL-based scheme relies on the allocated TAL. If the allocated TAL is inappropriate with respect to the UE's mobility and traffic characteristics, the TAL-based scheme may produce adverse effects. To find an optimal TAL allocation method for global UE units that exhibit weak regularity in their mobility, this paper develops an embedded Markov chain approach to analyze the signaling cost of the TAL-based scheme. This paper distinguishes itself from existing studies in the following aspects. First, this paper follows LTE technical specifications, that is, the number of TAs in a TAL can vary and, furthermore, is upper bounded, whereas existing studies partially or completely ignore this stipulation. Second, this paper emphasizes the impact of a call handling model that dictates whether a TAU occurs after the completion of a call by considering two call handling models, i.e., a call plus location update and a call without location update. Third, as for the dependence among the cell residence time, the TA residence time, and the TAL residence time, this paper proposes the use of a fluid flow model to describe this dependence, which is simple but does not compromise accuracy. Analytical formulas for the total signaling cost of the TAL-based scheme due to TAU and paging operations, as well as formulas that are useful in designing an optimal paging scheme, are derived, and their accuracy is validated through Mont Carlo simulation. Then, numerical studies are carried out to investigate the impact of diverse parameters on the signaling cost, revealing that the network can allocate, to a UE unit, an optimal TAL that is consistent with the UE's mobility and traffic characteristics to minimize the signaling cost of the TAL-based scheme.

Historical based location management strategies for PCS networks

Due to the current popularity of wireless communication, personal communication service networks have attracted a lot of attention. As mobile terminals (MTs) in such networks have the ability to communicate on the move, location management (LM) is a critical issue that should be handled carefully. Managing MTs locations is to simultaneously perform two main operations, which are; location update and paging. A good LM strategy maintains both operations with the minimum time and signaling penalties. Although several LM strategies have been introduced, they still suffer from several drawbacks. This paper introduces three novel LM strategies, which are; historical based location management (HBLM), direction based location management (DBLM) and trajectory based location management (TBLM). TBLM strategy is based on geographical position of MTs, while HBLM and DBLM are based on geographical position of MTs as well as time aspects. Visited locations are saved in MT's internal cache in the form of cell identifier as well as the corresponding time interval. Location tracking is fully supervised by the MT's current visitor location register (VLR). On the other hand, the collected location information in MT's cache is sent to VLR when MT passed through a previously defined number of cells or when a previously defined number of time periods has elapsed. In HBLM, paging is done according to the historical movements saved in VLR, while DBLM takes also MT's movement direction into consideration while in TBLM, paging is done according to the historical trajectories that MTs are used to follow. Experimental results have shown that the proposed LM strategies significantly improve MTs' tracking process as they introduce the minimum signaling penalty (for paging and registration) with an acceptable paging time delay compared with recent LM strategies.

Local Anchor Based Location Management Schemes for Small Cells in HetNets

Existing location management (LM) methods for macrocells in LTE-Advanced have tracking area list (TAL) granularity. Therefore, a user equipment (UE) triggers a location update (LU) whenever it leaves its current TAL, and it is searched through paging (PG) with TAL accuracy. However, these procedures are not well-suited for small cells (SCs). The reasons are twofold. First, dense deployments of SCs imply that paging has a low probability to be successful in the first attempt, increasing the signaling overhead in the core network (CN). Second, smaller coverage areas lead to a higher mobility among cells, increasing the signaling overhead in the CN due to LUs. In this work, two LM schemes with fine granularity are proposed. These schemes update UE's location to a local anchor (LA) in a SC or tracking area (TA) basis, respectively. By increasing the accuracy of UE's location, a significant reduction of signaling overhead in the CN due to PG is achieved. Moreover, LUs to the LA are performed through direct X2-interface links to avoid signaling overhead in the CN. A versatile mobility model is developed and closed-form expressions for UEs’ mobility metrics are found to validate the proposed schemes through variations of critical parameters such as TA/TAL configuration, UE's mobility patterns and cell residence times.

Distance-Based Location Management Utilizing Initial Position for Mobile Communication Networks

This paper aims at improving the distance-based location management scheme for mobile communication networks. In location management, a mobile terminal (MT) is tracked based on its location-update area (LA). The improvement is brought about by joint optimization of LA center and LA size. For LA center optimization (LCO), we determine the optimal center position of the LA given the initial position of the MT upon each location update. The investigation of optimal LA center has eluded research to date. Based on the popular continuous-time random walk (CTRW) mobility model, we propose an analytical framework that uses a diffusion equation to determine the optimal LA center that minimizes the total cost of location management, consisting of the location update cost and terminal paging cost. This framework allows us to easily model the non-Markovian movement of the MT and evaluate the impact of various measurable physical parameters (such as length of road section, angle between road sections, and road section crossing time) and LA center. In particular, we show that proper LA center can significantly reduce the total cost. For example, for the circular LA and low Poisson call-arrival rate, optimizing the LA center alone has the potential of reducing the cost by up to 37 percent. Joint optimization of the LA center and terminal paging scheme can reduce the cost even further. Simulations results match the theoretical analysis to a gap within 3 percent, indicating that our theoretical model is very accurate.

A Conceptual Approach to Location Management in Wireless Networks

In this paper, in terms of conceptual aspects, we highlight the various common key features and issues involved in the design of the location management scheme for wireless networks. Besides, regardless of supported network types, we briefly review and analyze the main features such as the conceptual basic ideas, key design principles and performance considerations on the existing location management schemes for wireless networks. We expect that the results can provide a comprehensive insight for designing more efficient location management scheme in future wireless networks as well as for fundamentally understanding the various existing location management schemes regardless of supported network types.