Michal Vondra - Academia.edu (original) (raw)

Papers by Michal Vondra

There is an increasing demand for in-flight broadband connectivity. Some airlines are already dep... more There is an increasing demand for in-flight broadband connectivity. Some airlines are already deployed satellite-based solutions, which have low data rate and high latency. In order to tackle these ...

2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), 2017

Aircraft is one of the last venues with no high-speed connectivity, which makes it an important r... more Aircraft is one of the last venues with no high-speed connectivity, which makes it an important research issue to address for both industry and academia. This paper introduces seamless gate-to-gate connectivity concept so that passengers can stay connected in all phases of the flight. The backhaul capacity is provided via direct air- to-ground communications links. Passengers can utilize both LTE and Wi-Fi access technologies on-board. In order to avoid interference with licensed ground LTE network, in-cabin LTE users will be served in the unlicensed spectrum via license assisted access (LAA) functionality when the aircraft is close to the ground. In this paper, we determine the altitude threshold for switching to LAA in order to provide seamless LTE connectivity. According to our analysis the myth about the 3 km threshold for the interference with the terrestrial network is not anymore valid. In addition, throughput and user data rates for LTE and Wi-Fi networks are investigated in different flight phases. We have found out that in-cabin LTE network can serve 80-240 users between 5-15 Mbps data rates, and Wi-Fi network can provide peak data rates of 14 Mbps in the worst-case scenario.

IEEE Transactions on Vehicular Technology, 2021

GLOBECOM 2017 - 2017 IEEE Global Communications Conference, 2017

On-board of aircraft is one of the last venues without high-speed connectivity, which makes it an... more On-board of aircraft is one of the last venues without high-speed connectivity, which makes it an important problem to address for both industry and academia. To this end, direct air-to-ground communications (DA2GC), where communication link is provided via direct link between aircraft and ground station, is a promising solution to provide high capacity and low latency backhaul capacity for aircraft. In this paper, we investigate the ground station deployment problem to provide 1.2 Gbps average backhaul capacity for each aircraft. The feasible operation points for the key network parameters: the number of ground stations, antenna array size, transmit power and bandwidth, are calculated. In addition, we propose a multi-user beamforming algorithm for dual-polarized hybrid DA2GC antenna arrays, and derive a tractable expression for the DA2GC cell throughput.

2018 IEEE Global Communications Conference (GLOBECOM), 2018

In this paper, we propose a model for beyond visual line of sight (BVLOS) operation for remote pi... more In this paper, we propose a model for beyond visual line of sight (BVLOS) operation for remote piloting of unmanned aerial vehicles (UAVs), which utilizes different technologies such as mobile edge computing and augmented reality. Ultra reliable low latency communication (URLLC) is a key service of 5G that enables safe BVLOS operation. Since message size of piloting signal is finite and communication channel is altitude dependent, we study reliability and latency under finite blocklength regime for different altitudes. In our numerical study, we find that for message sizes 30 and 50 bits, coded packet size, i.e., blocklength, should be in the range of 200 and 300 bits to enable BVLOS operation. We also found that minimum distance between UAVs to avoid any crash should be around 0.2 m for 15 m/s UAV speed and different altitudes ranging from 1.5 m to 120 m. According to our study, BVLOS operation of UAVs can be realized by URLLC by providing error probability in the vicinity of 10−310^{-3}10−3, and latency on the order of milliseconds for downlink communication with blocklength of tens to hundred bits.​

IEEE Systems Journal, 2016

IEEE Communications Magazine, 2017

IEEE Communications Magazine, 2017

Elektronika ir Elektrotechnika, 2016

By integrating computing capabilities to small cells, computation can be offloaded from a User Eq... more By integrating computing capabilities to small cells, computation can be offloaded from a User Equipment (UE) to so-called Small Cell Cloud (SCC). This concept takes advantage of proximity of users and small cells to shorten latency for mobile cloud computing applications. If a user decides to offload an application from the UE to the SCC, computing resources must be allocated at a proper cells, which can provide sufficient computation power and which ensure delivery of required results in time. In this paper, we propose an algorithm to balance load among cells with respect to the delay requirements imposed by the users. The algorithm also considers available computation resources of the small cells. Analytical results carried out in this paper confirm efficiency of the novel load balancing. Consequently, the proposed algorithm increases satisfaction of the users with the quality of service provided through the SCC.

2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013

ABSTRACT To ensure faultless handover procedure of mobile users, each cell in the network must es... more ABSTRACT To ensure faultless handover procedure of mobile users, each cell in the network must establish a Neighbor Cell List (NCL). The NCL contains adjacent cells to which handover can be performed. A problem related to the handover from a Macro/Micro cell (MeNB) appears with the rising density of cells with the limited coverage, so-called Small Cells (SCeNBs). By using method of the NCL creation described in standards or literature, the number of neighboring cells suitable for handover from the MeNB can be extensive. Therefore, we propose an algorithm for automatic creation of the NCL with reduced number of included cells. The proposed algorithm exploits knowledge of the last visited cell in combination with the statistical information on performed handovers in the past to determine the possibility of transition to the neighboring cells. As the results show, the proposed algorithm significantly reduces the number of cells in the NCL while the probability of missing handover target cell in the NCL is kept negligible.

IEEE Transactions on Vehicular Technology, 2016

2014 IEEE 3rd International Conference on Cloud Networking (CloudNet), 2014

ABSTRACT With increasing requirements of mobile users on computational demanding applications, th... more ABSTRACT With increasing requirements of mobile users on computational demanding applications, the need for offloading of computation to a cloud is a convenient way to provide high QoS and to lower energy consumption of a User Equipment (UE). However, common centralized cloud can prolong overall application processing time due to high delay of data delivery from the UE to the cloud and back. To reduce data delivery delay, a concept known as Small Cell Cloud (SCC) can be adopted. The SCC is based on equipping small cell base stations by additional computing capacity and enabling distributed computation for mobile cloud application. For proper function of the SCC, offloaded computing tasks must be efficiently and uniformly distributed among all computing cells. In this paper, we design the algorithm for selection of the computing cells that increases user’s satisfaction with experienced delay due to data transmission and computing. The algorithm selects the computing cell based on combination of users’ requirements and the SCC status. As the results show, the proposed algorithm is able to provide higher satisfaction comparing to competitive approaches for all types of backhauls while the balancing of load is not significantly affected.

2014 IFIP Wireless Days (WD), 2014

This deliverable defines general framework for consequent technical workpackages in TROPIC. First... more This deliverable defines general framework for consequent technical workpackages in TROPIC. First, scenarios from the business point of view are defined and further transformed to more technical representation. Then, abstraction models are introduced for both communication and computation parts of femto-cloud concept. Furthermore, requirements need to be met to ensure efficient and feasible utilization of the femto-cloud are presented. To enable prove of the femto-cloud concept and to compare the developed techniques and algorithms a set of performance indicators to be considered in all technical workpackages are listed and defined. To that end, the models and simulation settings are defied in the last section of the document

2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013

There is an increasing demand for in-flight broadband connectivity. Some airlines are already dep... more There is an increasing demand for in-flight broadband connectivity. Some airlines are already deployed satellite-based solutions, which have low data rate and high latency. In order to tackle these ...

2017 IEEE 86th Vehicular Technology Conference (VTC-Fall), 2017

Aircraft is one of the last venues with no high-speed connectivity, which makes it an important r... more Aircraft is one of the last venues with no high-speed connectivity, which makes it an important research issue to address for both industry and academia. This paper introduces seamless gate-to-gate connectivity concept so that passengers can stay connected in all phases of the flight. The backhaul capacity is provided via direct air- to-ground communications links. Passengers can utilize both LTE and Wi-Fi access technologies on-board. In order to avoid interference with licensed ground LTE network, in-cabin LTE users will be served in the unlicensed spectrum via license assisted access (LAA) functionality when the aircraft is close to the ground. In this paper, we determine the altitude threshold for switching to LAA in order to provide seamless LTE connectivity. According to our analysis the myth about the 3 km threshold for the interference with the terrestrial network is not anymore valid. In addition, throughput and user data rates for LTE and Wi-Fi networks are investigated in different flight phases. We have found out that in-cabin LTE network can serve 80-240 users between 5-15 Mbps data rates, and Wi-Fi network can provide peak data rates of 14 Mbps in the worst-case scenario.

IEEE Transactions on Vehicular Technology, 2021

GLOBECOM 2017 - 2017 IEEE Global Communications Conference, 2017

On-board of aircraft is one of the last venues without high-speed connectivity, which makes it an... more On-board of aircraft is one of the last venues without high-speed connectivity, which makes it an important problem to address for both industry and academia. To this end, direct air-to-ground communications (DA2GC), where communication link is provided via direct link between aircraft and ground station, is a promising solution to provide high capacity and low latency backhaul capacity for aircraft. In this paper, we investigate the ground station deployment problem to provide 1.2 Gbps average backhaul capacity for each aircraft. The feasible operation points for the key network parameters: the number of ground stations, antenna array size, transmit power and bandwidth, are calculated. In addition, we propose a multi-user beamforming algorithm for dual-polarized hybrid DA2GC antenna arrays, and derive a tractable expression for the DA2GC cell throughput.

2018 IEEE Global Communications Conference (GLOBECOM), 2018

In this paper, we propose a model for beyond visual line of sight (BVLOS) operation for remote pi... more In this paper, we propose a model for beyond visual line of sight (BVLOS) operation for remote piloting of unmanned aerial vehicles (UAVs), which utilizes different technologies such as mobile edge computing and augmented reality. Ultra reliable low latency communication (URLLC) is a key service of 5G that enables safe BVLOS operation. Since message size of piloting signal is finite and communication channel is altitude dependent, we study reliability and latency under finite blocklength regime for different altitudes. In our numerical study, we find that for message sizes 30 and 50 bits, coded packet size, i.e., blocklength, should be in the range of 200 and 300 bits to enable BVLOS operation. We also found that minimum distance between UAVs to avoid any crash should be around 0.2 m for 15 m/s UAV speed and different altitudes ranging from 1.5 m to 120 m. According to our study, BVLOS operation of UAVs can be realized by URLLC by providing error probability in the vicinity of 10−310^{-3}10−3, and latency on the order of milliseconds for downlink communication with blocklength of tens to hundred bits.​

IEEE Systems Journal, 2016

IEEE Communications Magazine, 2017

IEEE Communications Magazine, 2017

Elektronika ir Elektrotechnika, 2016

By integrating computing capabilities to small cells, computation can be offloaded from a User Eq... more By integrating computing capabilities to small cells, computation can be offloaded from a User Equipment (UE) to so-called Small Cell Cloud (SCC). This concept takes advantage of proximity of users and small cells to shorten latency for mobile cloud computing applications. If a user decides to offload an application from the UE to the SCC, computing resources must be allocated at a proper cells, which can provide sufficient computation power and which ensure delivery of required results in time. In this paper, we propose an algorithm to balance load among cells with respect to the delay requirements imposed by the users. The algorithm also considers available computation resources of the small cells. Analytical results carried out in this paper confirm efficiency of the novel load balancing. Consequently, the proposed algorithm increases satisfaction of the users with the quality of service provided through the SCC.

2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013

ABSTRACT To ensure faultless handover procedure of mobile users, each cell in the network must es... more ABSTRACT To ensure faultless handover procedure of mobile users, each cell in the network must establish a Neighbor Cell List (NCL). The NCL contains adjacent cells to which handover can be performed. A problem related to the handover from a Macro/Micro cell (MeNB) appears with the rising density of cells with the limited coverage, so-called Small Cells (SCeNBs). By using method of the NCL creation described in standards or literature, the number of neighboring cells suitable for handover from the MeNB can be extensive. Therefore, we propose an algorithm for automatic creation of the NCL with reduced number of included cells. The proposed algorithm exploits knowledge of the last visited cell in combination with the statistical information on performed handovers in the past to determine the possibility of transition to the neighboring cells. As the results show, the proposed algorithm significantly reduces the number of cells in the NCL while the probability of missing handover target cell in the NCL is kept negligible.

IEEE Transactions on Vehicular Technology, 2016

2014 IEEE 3rd International Conference on Cloud Networking (CloudNet), 2014

ABSTRACT With increasing requirements of mobile users on computational demanding applications, th... more ABSTRACT With increasing requirements of mobile users on computational demanding applications, the need for offloading of computation to a cloud is a convenient way to provide high QoS and to lower energy consumption of a User Equipment (UE). However, common centralized cloud can prolong overall application processing time due to high delay of data delivery from the UE to the cloud and back. To reduce data delivery delay, a concept known as Small Cell Cloud (SCC) can be adopted. The SCC is based on equipping small cell base stations by additional computing capacity and enabling distributed computation for mobile cloud application. For proper function of the SCC, offloaded computing tasks must be efficiently and uniformly distributed among all computing cells. In this paper, we design the algorithm for selection of the computing cells that increases user’s satisfaction with experienced delay due to data transmission and computing. The algorithm selects the computing cell based on combination of users’ requirements and the SCC status. As the results show, the proposed algorithm is able to provide higher satisfaction comparing to competitive approaches for all types of backhauls while the balancing of load is not significantly affected.

2014 IFIP Wireless Days (WD), 2014

This deliverable defines general framework for consequent technical workpackages in TROPIC. First... more This deliverable defines general framework for consequent technical workpackages in TROPIC. First, scenarios from the business point of view are defined and further transformed to more technical representation. Then, abstraction models are introduced for both communication and computation parts of femto-cloud concept. Furthermore, requirements need to be met to ensure efficient and feasible utilization of the femto-cloud are presented. To enable prove of the femto-cloud concept and to compare the developed techniques and algorithms a set of performance indicators to be considered in all technical workpackages are listed and defined. To that end, the models and simulation settings are defied in the last section of the document

2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013