Basic Service Set Research Articles

Non-Satellite Broadband Maritime Communications for e-Navigation Services

The development of broadband network access technologies available to users on land has triggered a rapid expansion of a diverse range of services provided by terrestrial networks. However, due to limitations of digital communication technologies in the off-shore area, the maritime ICT systems evolution so far has not followed that trend. Despite the e-navigation initiative defining the set of Maritime Services, the progress in the maritime ICT systems evolution has been slow. Only a few systems, including the VHF Data Exchange System (VDES), or the TRI-Media Telematic Oceanographic Network (TRITON) have been proposed to extend the basic set of services offered by classical radio-communication solutions. However, all those systems have significant limitations. The purpose of this paper is to introduce the netBaltic system designed as a fully heterogeneous system for modern maritime communications. Its unique feature is the capability to transparently use different communication technologies to efficiently support maritime ICT services, as well as openness for the incorporation of future communication technologies. The paper presents an overview of VDES, TRITON and netBaltic systems and analysis showing their expected strengths and weaknesses. The systems are then compared in simulated environments, illustrating real-world usage scenarios based on real maritime traffic information and performance measurements obtained during off-shore measurement campaigns. Results indicate that netBaltic seems to be the most versatile one and is capable of offering access to all services defined by International Maritime Organization, due to its ability to use different communication technologies simultaneously and functionality offered by its Delay Tolerant Networking component.

Adaptive Indoor Localization System for Large-Scale Area

Generally, fingerprint-based indoor localization works inefficiently when deployed in a large-scale area. This is because it consumes massive resources and takes long processing time for searching the exact location in the large fingerprint database. Moreover, the changing environment can degrade overall performance. To tackle these problems, we propose an adaptive indoor localization system for a large-scale area. Our system consists of three main parts. First, our area classification algorithm is the key to overcome the problem caused by the large-scale area. It identifies an area of the user’s queries whether they are outdoor or located in a specific building. Specifically, the algorithm can filter out the queries sent from outdoor or out-of-scope areas. Then, the information of this part is sent to the next part. Second, our fingerprint-based indoor localization algorithm can utilize the information from the first part by searching only the fingerprint in the specific building. This can significantly reduce searching space and processing time in order to localize the exact location. Third, our missing-BSSID detector algorithm detects the missing Basic Service Set Identifiers (BSSIDs) in the incoming query and updates a sampling database. This part is for our system to quickly adapt to the changing environment. We evaluated and deployed our system in a large-scale exhibition including 37 multi-floor buildings, covering 486,000 m2 and generating approximately 600,000 records of queries from users. In addition, we created a simulation to evaluate our system in the critically-changing environment. Our proposed system achieves high accuracy. More importantly, our area classification algorithm can significantly reduce the overall processing time compared to the previous work. Also, we showed that when applying our missing-BSSID detector algorithm to our system as well as other existing systems, the overall system performance can be significantly improved.

Implementation of international legal standards of "cultural service" in the modern system of public and legal support of the population with social-cultural services

The article, based on the analysis of scientific, empirical and journalistic sources, testifies to the need to study the state and problems of implementation of international legal standards of "cultural service" in the modern system of public legal provision of social and cultural services using the necessary administrative and legal tools. The specifics of international legal documents to ensure the implementation of socio-cultural rights and freedoms of citizens, which is to solve legal, technical, scientific and administrative problems of the industry. The basic documents developed by international organizations affect not only the national legislation of the member states, but also the use of experience, which in turn contributes to the optimization of the system of cultural services. The main attention is paid to the world standards of regulation of cultural space and provision of cultural services to the population, which are enshrined in the most important international legal documents on culture, which are established through the prism of the implementation of the EU-Ukraine Association Agreement. Emphasis is placed on the permanent imperfection of the current "cultural" legislation and systemic miscalculations in the issues of legal provision of the population with a quality cultural product, which is confirmed by the data of the sociological survey, according to which 58.1% of respondents guarantees of providing citizens with cultural services (basic set of cultural services) are called those that require significant improvement. Emphasis is placed on the importance of international legal norms, which act as the main regulator of "cultural" legal relations, because their regulations lay down the basic principles on which the national "cultural" law of a country should be based. It is international acts that allow the formation of unified norms for the regulation of legal relations in the cultural sphere.

Socio-economic conditions as a factor of revealing cities’ marketing potential

The object of the study are the socio-economic conditions of cities as the basis of marketing potential. The purpose of the study is to identify the role of socio-economic conditions in revealing the marketing potential of cities. The main methods used for the study are matching, comparison, ranking. Our conclusion is that socio-economic conditions cannot always be perceived as the basis for revealing the marketing potential of a city, which is proved by independent studies of the authors, as well as by the analysis of data obtained in the course of other studies. It was possible to establish that socio-economic conditions do not guarantee permanent population growth for cities: the affordability of a basic set of goods and services, a competitive level of income, the availability of higher education institutions and the saturation with health and cultural facilities are not necessarily highly rated by real and potential local residents. This allows us to speak about the need for marketing efforts to attract consumers of a territorial product (socio-economic conditions of a city), it is not enough to have any advantages – it is important to be able to draw attention to them, to ensure the formation of the necessary attitudes regarding the socio-economic conditions of life in cities. Therefore, we are speaking about the need to take into account the nature of consumer demand for the socio-economic conditions of cities and the use of the appropriate type of marketing. The authors have examined a number of examples of applying city types of marketing, such as conversion, incentive, supportive, synchromarketing, remarketing and demarketing.

Analysis and Optimization of Channel Bonding in Dense IEEE 802.11 WLANs

Channel bonding in IEEE 802.11 wireless LANs is a technique whereby adjacent 20MHz channels are ‘bonded’ to create a wider bandwidth channel that supports higher data rate transmissions. Although rate improvements due to channel bonding has been shown in sparse wireless LAN environments, its effectiveness in dense scenarios requires further exploration due to increased sensitivity to interference from overlapping co-channel basic service sets. With the newly finalized 802.11ax standard supporting enhanced spatial reuse feature, its impact on the expected gains from channel bonding needs careful analysis. In this work, we propose a new analytical framework that accurately models the performance of channel bonding as a function of both PHY and MAC parameters for a dense network scenario. A new channel bonding algorithm that is robust to overlapped co-channel interference is described, i.e. it preserves channel bonding gains by intelligently choosing the channel bonding bandwidth based on network conditions and parameters that are readily available to all stations, critically the modulation scheme chosen for packet transmission. The predicted gains of the proposed algorithm are verified via comprehensive simulations conducted with the open source network simulator ns-3.

Performance analysis and evaluation of IEEE 802.11 distributed coordination function using OPNET

This paper discusses the distributed coordination function (DCF) access mechanism which is a carrier sense multiple access with collision avoidance (CSMA/CA) scheme. Simulation projects for different DCF performance parameters have been built using the OPNET network simulator. The projects are mainly basic service set (BSS) topology simulated under different parameter values (data rate, fragmentation, RTS/CTS, number of nodes, and load condition). Simulation results show when the DCF access mechanism is better under what load condition, and how to choose the best fragmentation threshold and other access-mechanism specific parameters according to the network conditions. Simulation results were validated against a theoretically calculated maximum throughput (the simulation maximum throughput was about 70% of the theoretically calculated maximum throughput).

ОСНОВНІ ПРОБЛЕМИ ЗДІЙСНЕННЯ ДІЯЛЬНОСТІ ЗАКЛАДАМИ КУЛЬТУРИ В УМОВАХ ДЕЦЕНТРАЛІЗАЦІЇ

The culture has always been funded residually. And now funding continues to be made available to address the immediate needs of communities. Subventions received by communities as part of the reform were aimed at road mending, renovating municipal equipment, water suppling, and upgrading. As a result, it is impossible to maintain cultural institutions and provide quality cultural services to the population in less well-off communities. This may result in depressed territories being left without cultural facilities, cultural programs and projects. Another problem that exists in villages, towns and small towns is the so-called «staff shortage». Low wages and lack of professional prospects in rural areas don’t help involvement of experts to work for positions in the field of culture. In the more capable ATCs, as well as in the communities that have become the centers of the community, there is often at least a team of the director, the artistic director, the circle leaders who organize the cultural life in the community. But in small villages, in houses of culture, the enthusiasm of only one person who has worked in this position all his life is still held. This person is at the same time a director, artistic director, head of all circles, and sometimes a technical worker. According to R. Yu. Mylian, increased attention to solving problems of the sociocultural development of rural settlements will contribute to the preservation and development of cultural institutions in rural areas, prevent the outflow of the working and most educated population, especially young people, and will eventually strengthen the sustainable development potential of Ukraine as a whole. The organization and holding of mass cultural events in rural areas is an effective means of strengthening the competitiveness of rural areas, enhances the development of cultural interregional and cross-border cooperation, event-tourism and has a positive impact on the branding of rural settlements as tourist attractions. To address the above issues, is invited to identify an approach whereby a State, acting by the Culture Ministry, will develop standards for the minimum volume and quality of cultural services, compliance with which will be mandatory for local governments in communities. This may occur by defining and establishing a set of basic services guaranteed by the State and financed from the State budget. For the normal functioning of State culture, it is necessary to establish a new concept of these institutions activities in the ATC, to provide for tax exemption by legal acts and to clearly define the types of services provided by cultural activity.

FINANCIAL LITERACY OF THE POPULATION: DIFFERENTIATION BY FEDERAL DISTRICTS

The article presents a secondary analysis of the results of all-Russian population surveys aimed at studying financial accessibility to the basic set of financial services of the entire population of the country, as well as small and medium-sized businesses. The authors draw attention to the significant differentiation of the financial knowledge indicator values across the Federal districts of Russia and the dynamics of this indicator. The results obtained cannot be interpreted unambiguously due to the closed nature of the source data. It is concluded that it is necessary to further study the identified differences in order to ensure the effectiveness of Federal and regional authorities to improve financial literacy of Russians.

Utility Maximization of Capacity Entropy for Dense IEEE 802.11ax WLANs based on Interference Characteristics

Internet of Things (IoT) is a kind of information carrier, which enables for all ordinary objects that can perform independent functions to realize interconnection. The standardization process of wireless local area networks (WLANs) which is an important network system of IoT is gradually advancing. IEEE 802.11ax will replace IEEE 802.11a/b/g/n/ac as the latest WLANs standard. The uplink transmission of IEEE 802.11ax adopts a hybrid access mode. The mode means that the stations (STAs) can access the network adopting either scheduling access mode or random access mode. Since the hybrid access mode supports both the scheduling and random access, how to allocate the resources among the STAs which adopt the two access modes is the first problem to be solved. In particular, IEEE 802.11ax focuses more on the network performance of the high-dense deployment scenarios. The characteristic of the interference of the overlapping basic service set (OBSS) situation is the key factor of the efficiency of resource allocation algorithm. Therefore, firstly, this paper combines capacity entropy multi-user access (CEM) with utility function, and defines a metric value to measure the utility of two kinds of users. Secondly, the simulation-assisted method is used to obtain the probability distribution characteristic of the interference power random variables from dense multi-cell scenarios of IEEE 802.11ax. Then, based on interference power random variables which generated by the probability density curve obtained by simulation, we propose an algorithm which can maximizetotal utility of scheduling and random access STAs, i.e., to maximize the total satisfaction of all STAs. The authors believe that the research can enhance the quality of experience (QoE) of users in dense multi-cell scenarios for the next generation WLANs.

A suggested approach to site storage resources in transmission planning models

Abstract

Constrained channel bonding based on maximum achievable throughput in WLANs

In Wireless Local Area Networks, channel bonding allows several basic channels to constitute a wide channel. The wide channel can increase potential throughput in a single Basic Service Set (BSS). However, channel contention among BSSs is more serious because the number of non-overlapping channels decreases. Therefore, the appropriate channel bandwidth should be chosen to improve the throughput of the whole network. In this paper, to control channel contention and improve throughput, we propose a channel bonding algorithm in which the channel bandwidth is constrained based on the achievable throughput analysis. At first, the channel contention relationship among BSSs is obtained according to the topology of the network. In each possible channel bonding and channel allocation scheme, the achievable throughput can be calculated according to the contention graph and the maximal clique algorithm. Then, the channel bonding scheme with the maximum achievable throughput can be selected. In the selected channel bonding scheme, each BSS uses a specific channel which consists of several basic channels, and these basic channels are candidate channels of constrained channel bonding in this BSS. Finally, constrained channel bonding will be performed in each BSS, and the combined wide channel can only be constituted by some or all of candidate basic channels. In this manner, channel contention among BSSs can be controlled. Simulation results show that the proposed constrained channel bonding achieves better performance than traditional channel bonding.

Algorithmic Identification of the Best WLAN Protocol and Network Architecture for Internet-Based Applications

This research developed a novel algorithm to evaluate internet-based services such as VoIP, Video Conferencing, HTTP and FTP, of different IEEE 802.11 technologies in order to identify the optimum network architecture among Basic Service Set (BSS), Extended Service Set (ESS) and the Independent Basic Service Set (IBSS). The proposed algorithm will yield the rank order of different IEEE 802.11 technologies. By selecting the optimum network architecture and technology, the best overall network performance that provides good voice, video and data quality is guaranteed. Furthermore, it meets the acceptance threshold values for the VoIP, Video Conferencing, HTTP and FTP quality metrics. This algorithm was applied to various room sizes ranging from [Formula: see text][Formula: see text]m to [Formula: see text][Formula: see text]m and the number of nodes ranged from 1 to 65. The spatial distributions considered were circular, uniform and random. The Quality of Service (QoS) metrics used were delay, jitter, throughput and packet loss.

Machine Learning Enabled Spectrum Sharing in Dense LTE-U/Wi-Fi Coexistence Scenarios

The application of Machine Learning (ML) techniques to complex engineering problems has proved to be an attractive and efficient solution. ML has been successfully applied to several practical tasks like image recognition, automating industrial operations, etc. The promise of ML techniques in solving non-linear problems influenced this work which aims to apply known ML techniques and develop new ones for wireless spectrum sharing between Wi-Fi and LTE in the unlicensed spectrum. In this work, we focus on the LTE-Unlicensed (LTE-U) specification developed by the LTE-U Forum, which uses the duty-cycle approach for fair coexistence. The specification suggests reducing the duty cycle at the LTE-U base-station (BS) when the number of co-channel Wi-Fi basic service sets (BSSs) increases from one to two or more. However, without decoding the Wi-Fi packets, detecting the number of Wi-Fi BSSs operating on the channel in real-time is a challenging problem. In this work, we demonstrate a novel ML-based approach which solves this problem by using energy values observed during the LTE-U OFF duration. It is relatively straightforward to observe only the energy values during the LTE-U BS OFF time compared to decoding the entire Wi-Fi packet, which would require a full Wi-Fi receiver at the LTE-U base-station. We implement and validate the proposed ML-based approach by real-time experiments and demonstrate that there exist distinct patterns between the energy distributions between one and many Wi-Fi AP transmissions. The proposed ML-based approach results in a higher accuracy (close to 99% in all cases) as compared to the existing auto-correlation (AC) and energy detection (ED) approaches.

Interference Steering to Manage Interference in IoT

Internet of Things (IoT) is a new paradigm that involves the interconnection of thousands of devices and home appliances. Due to the scarcity of the spectrum suitable for wireless electromagnetic transmission, many communication systems and devices are close to each other, or even overlapping in spectrum, thus incurring complicated interference situations. Therefore, interference in IoT is worthy of thorough investigation and should be well addressed. There have been numerous interference management (IM) proposals at the interfering transmitter or the interfered transmitter/receiver separately or cooperatively. Moreover, the existing IM schemes rely mainly on the use of channel state information (CSI). However, in some communication scenarios, the option to adjust the interferer is not available, and, in the case of downlink transmission, it is always difficult or even impossible for the interfered receiver to acquire necessary information for IM. Based on the above observations, we first propose a novel IM technique, called interference steering (IS). By making use of both CSI with respect to and data carried in the interfering signal, IS generates a signal to modify the spatial feature of the original interference, so that the steered interference at the interfered receiver is orthogonal to its intended signal. We then apply IS to a wireless local area network (WLAN)-based IoT in which the same frequency band is reused by adjacent basic service sets (BSSs) with overlapping areas. With IS, multiple nearby access points (APs) could simultaneously transmit data on the same channel to their mobile stations (STAs), thus enhancing spectrum reuse. Our in-depth simulation results show that IS significantly improves network SE over existing IM schemes.

Integrated platform solutions and quality management in the planning and organization of production processes

The article deals with the task of coordinating digital and industrial platforms in the context of interaction between the subjects of the digital economy. Digital transformation should occur against the background of the systematic introduction of modern corporate governance methods, including: investment management, project management, financial management, personnel management, knowledge management, etc. The authors clarify the possibility of using ontologically oriented intellectual methods to support planning and organization of production processes. The article shows that the use of intelligent methods in building platform solutions begins with identifying, classifying and describing the main processes of an enterprise, establishing their sequence and interconnection. The authors propose ontologically oriented methods for coordinating the management and planning of production processes. The models are presented of production data support scenarios in accordance with the requirements of business processes. In addition, in addition to the production process scenarios, the solution includes a set of typical user access scenarios and basic data transfer services by experts.

Access to abortion of undocumented migrants seen by Médecins du Monde in the Humanitarian Hub

Abstract As of June 2017, the population of the Maximillian Park (an undocumented migrant camp in Brussels) is mainly Eritrean and Sudanese migrants who intend to continue their journey to the United Kingdom (Depraetere, 2017; Daher, 2018). In response to demanding needs, Médecins du Monde together with 8 organisations, created a one-stop service centre, The Humanitarian Hub, in January 2018 to offer a set of basic services to the migrants. The Hub implemented a voluntary de-medicalized midwifery clinic. The medical team noted an under-representation of women, 40 out of 745 (5,4%), while the coordination team identified a number of complex unwanted pregnancies, many of which relating to violence. Accessing free abortion for undocumented women in Belgium requires the Urgent Medical Assistance certificate. This often takes several weeks, making it unrealistic to obtain in time for an abortion. Accordingly, the women or family planning centres cover the financial cost. The Hub’s midwifery clinic thus focused on building trust with the women, and facilitated referrals to family planning centres. By taking steps to create a more gender-sensitive Hub, the proportion of women seeking consultations doubled. In 2018, 955 out of 8990 (10,6%) patients were women, totalling 324 midwifery consultations. 65 of these women were pregnant, and the 23 who sought abortion were referred to family planning centres. None had Urgent Medical Assistance. It is crucial to consider the particularities of a population and their social determinants of health when implementing a holistic system. For instance, focusing on violent experiences in medical consultations can help better understand women’s situation. The coordination between The Hub and family planning centres helped in reducing barriers for migrant women. The project has seen success, thanks to the flexibility of the family planning centres in quickly receiving these pregnant women, and to the four centres who covered abortion costs. Key messages It is evident that the magnitude of these women’s situation is undervalued, thus it is important to increase sensitization and advocacy in order to offer them greater support. The Hub has provided a number of services for undocumented migrants, notably abortion, and removed some barriers in accessing care. However, it is a fragile solution to a structural problem.

A spatial clustering group division-based OFDMA access protocol for the next generation WLAN

The next generation wireless local area network (WLAN) needs to significantly improve the area throughput in high-dense deployment scenario. Orthogonal frequency division multiple access (OFDMA), considered as the key technology of the next generation WLAN, has been adopted by IEEE 802.11ax. However, most existing studies have one tricky problem: interference extension problem, i.e., the stations (STAs) placed at dispersive locations from one basic service set (BSS) access channel and transmit data simultaneously through OFDMA, thereby interfering a large area and suppressing the potential transmissions around this BSS. Unfortunately, high-dense deployment scenario exacerbates interference extension problem. This article proposes a spatial clustering group division-based OFDMA (SCGD-OFDMA) protocol, which enables the geographically close STAs to form spatial clustering groups, named SCGs. Each SCG has a leader STA and several member STAs. Each SCG’s leader STA contends for channel resources. After that, the leader STAs that successfully contending channel are scheduled by the access point one by one to trigger its member STAs to transmit uplink data by using OFDMA. Therefore, the geographical interference area is reduced and the area throughput is improved since the concurrent STAs in one SCG are located in limited area. This article theoretically analyzes the optimal SCG establishment, and throughput and area throughput of SCGD-OFDMA. Theoretical analysis is consistent with simulation results. The simulation results also show that when the number of STAs is 200 and all resource units are used for random access, SCGD-OFDMA outperforms IEEE 802.11ax and OMAX in area throughput by 56.13% and 190.97%, respectively.

Multiple BSSs Association Based Spatial Clustering Group Access Protocol for Next Generation WLAN

The next generation Wireless Local Area Network (WLAN) IEEE 802.11be regards Extremely High Throughput (EHT) as its core technology goal, among which multi-band capability and AP cooperation technology are regarded as its key technologies. However, the existing research on Orthogonal Frequency Division Multiple Access (OFDMA) protocol does not consider the multi-band capability and AP collaboration technology of IEEE 802.11be, so the improvement of system performance is limited and does not meet the EHT requirement. Especially when the nodes in overlapping coverage area have a large number of traffic, it is more important to improve the throughput of nodes in overlapping coverage area. In order to improve the throughput of nodes in overlapping coverage area, this paper proposes a spatial clustering group OFDMA protocol associated with multiple Basic Service Sets (BSSs). The protocol allows nodes in overlapping coverage area to be associated with multiple BSSs at the same time by using multi-band capability, that is, multi-association; Using AP collaboration technology allows nodes to perform parallel backoff with channels on multiple BSSs to improve access efficiency. Nodes in the overlapping coverage area are associated with the channels of multiple BSSs for parallel backoff. Node completed backoff and successfully accessed triggers a spatial clustering group (SCG) with close to its spatial location. OFDMA mode is used by SCG to access and transmit, thus increasing the access opportunities of nodes within overlapping coverage, thereby improving the throughput. The simulation results show that using the SCG-OFDMA protocol proposed in this paper associated with two BSSs, its throughput of nodes within overlapping coverage can achieve 353.41% higher than the IEEE 802.11ax protocol and 558.33% higher than the OMAX protocol respectively.

Damysus: A Practical IEEE 802.11ax BSS Color Aware Rate Control Algorithm

Institute of Electrical and Electronics Engineers (IEEE) 802.11ax Spatial Reuse (SR) is a new feature in the IEEE 802.11 family, aiming at improving the spectrum efficiency and the network performance in dense deployments. The main and perhaps the only SR technique in that amendment is the Basic Service Set (BSS) Color. It aims at increasing the number of concurrent transmissions in a specific area, based on a newly defined Overlapping BSS/Preamble-Detection threshold. In this paper, we overview the latest developments introduced in the IEEE 802.11ax for the SR and propose a rate control algorithm developed to exploit the BSS Color scheme. Our proposed algorithm, Damysus is specifically designed to function in dense environments where other off-the-shelf algorithms show poor performance. Simulation results in various dense scenarios, show a clear performance improvement of up to 113% gain in throughput over the well known MinstrelHT algorithm.

Handling real-time communication in infrastructured IEEE 802.11 wireless networks: The RT-WiFi approach

In this paper, the RT-WiFi architecture is proposed to handle real-time (RT) communication in infrastructured IEEE 802.11 networks operating in high density industrial environments. This architecture is composed of a time division multiple access (TDMA)-based coordination layer that schedules the medium access of RT traffic flows, and an underlying traffic separation mechanism that is able do handle the coexistence of RT and non-RT traffic sources in the same communication environment. The simulation assessment considers an overlapping basic service set (OBSS), where a set of RT and non-RT stations share the same frequency band. The performance assessment compares the behaviour of the RT-WiFi architecture vs. the behaviour of standard distributed coordination function (DCF), point coordination function (PCF), enhanced distributed channel access (EDCA), and hybrid coordination function (HCF) controlled channel access (HCCA) medium access control mechanisms. A realistic error-prone model has been used to measure the impact of message losses in the RT-WiFi architecture. It is shown that the proposed RT-WiFi architecture offers a significantly enhanced behaviour when compared with the use of IEEE 802.11 standard mechanisms, in what concerns average deadline misses and average access delays. Moreover, it also offers an almost constant access delay, which is a relevant characteristic when supporting RT applications.