CINR Performance of Downlink Mobile WiMAX IEEE 802.16e Deployed Using Coexistence Cellular Terrestrial and HAPS

Deploying WiMAX through High Altitude Platform Station (HAPS) system is a new means of wireless delivery method and thus attracting much the attention in a telecommunication society. However delivering WiMAX through the terrestrial network has already been started a few years ago. Therefore, we need to look at the scenario of coexistence system both of HAPS and terrestrial in delivering WiMAX services. This paper evaluates the performance of coexistence system between cellular HAPS and terrestrial for the downlink scenario when they are transmitting WiMAX mobile 802.16e services. Our evaluation is based on the performance simulation of coexistence model using two methods. First method is a footprint exchange between the two systems.The second method is a combination of footprint exchange and HAPS footprint enhancement. The proposed methodsare then evaluated by computer simulation in terms of carrier to interference plus noise ratio (CINR) performance. In general, both methods resulting performance enhancement in CINR quality compared with coexistence deployment with normal scenario of the cell configuration used by HAPS and terrestrial. The method of combining footprint exchange and HAPS footprint enhancement is able to improve CINR more than 10 dB compared with the normal footprint configuration for all users location inside the coverage

Performance Evaluation of WiMAX Broadband from High Altitude Platform Cellular System and Terrestrial Coexistence Capability

The performance obtained from providing worldwide interoperability for microwave access (WiMAX) from high altitude platforms (HAPs) with multiple antenna payloads is investigated, and the coexistence capability with multiple-operator terrestrial WiMAX deployments is examined. A scenario composed of a single HAP and coexisting multiple terrestrial WiMAX base stations deployed inside the HAP coverage area (with radius of 30 km) to provide services to fixed users with the antenna mounted on the roof with a directive antenna to receive signals from HAPs is proposed. A HAP cellular configuration with different possible reuse patterns is established. The coexistence performance is assessed in terms of HAP downlink and uplink performance, interfered by terrestrial WiMAX deployment. Simulation results show that it is effective to deliver WiMAX via HAPs and share the spectrum with terrestrial systems

Performance Evaluation of WiMAX Broadband from High Altitude Platform Cellular System and Terrestrial Coexistence Capability

The performance obtained from providing worldwide interoperability for microwave access (WiMAX) from high altitude platforms (HAPs) with multiple antenna payloads is investigated, and the coexistence capability with multiple-operator terrestrial WiMAX deployments is examined. A scenario composed of a single HAP and coexisting multiple terrestrial WiMAX base stations deployed inside the HAP coverage area (with radius of 30&#8201;km) to provide services to fixed users with the antenna mounted on the roof with a directive antenna to receive signals from HAPs is proposed. A HAP cellular configuration with different possible reuse patterns is established. The coexistence performance is assessed in terms of HAP downlink and uplink performance, interfered by terrestrial WiMAX deployment. Simulation results show that it is effective to deliver WiMAX via HAPs and share the spectrum with terrestrial systems.</p

The Coverage, Capacity and Coexistence of Mixed High Altitude Platform and Terrestrial Segments

This thesis explores the coverage, capacity and coexistence of High Altitude Platform (HAP) and terrestrial segments in the same service area. Given the limited spectrum available, mechanisms to manage the co-channel interference to enable effective coexistence between the two infrastructures are examined. Interference arising from the HAP, caused by the relatively high transmit power and the antenna beam profile, has the potential to significantly affect the existing terrestrial system on the ground if the HAP beams are deployed without a proper strategy. Beam-pointing strategies exploiting phased array antennas on the HAPs are shown to be an effective way to place the beams, with each of them forming service cells onto the ground in the service area, especially dense user areas. Using a newly developed RF clustering technique to better point the cells over an area of a dense group of users, it is shown that near maximum coverage of 96% of the population over the service area can be provided while maintaining the coexistence with the existing terrestrial system. To improve the user experience at the cell edge, while at the same time improving the overall capacity of the system, Joint Transmission – Coordinated Multipoint (JT-CoMP) is adapted for a HAP architecture. It is shown how the HAP can potentially enable the tight scheduling needed to perform JT-CoMP due to the centralisation of all virtual E-UTRAN Node Bs (eNodeBs) on the HAP. A trade-off between CINR gain and loss of capacity when adapting JT-CoMP into the HAP system is identified, and strategies to minimise the trade-off are considered. It is shown that 57% of the users benefit from the JT-CoMP. In order to enable coordination between the HAP and terrestrial segments, a joint architecture based on a Cloud – Radio Access Network (C-RAN) system is introduced. Apart from adapting a C-RAN based system to centrally connect the two segments together, the network functional split which varies the degree of the centralised processing is also considered to deal with the limitations of HAP fronthaul link requirements. Based on the fronthaul link requirements acquired from the different splitting options, the ground relay station diversity to connect the HAP to centralised and distributed units (CUs and DUs) is also considered

Μεταφορά και Διαχείριση Ευρυζωνικής Κίνησης σε Ασύρματα Τηλεπικοινωνιακά Δίκτυα

Αντικείμενο της παρούσας διατριβής αποτελεί η μελέτη των τεχνικών διαχείρισης πόρων σε ασύρματα ευρυζωνικά δίκτυα επικοινωνιών με στόχο την βελτιστοποίηση της φασματικής απόδοσης καθώς και η μελέτη εναλλακτικών τεχνολογιών μεταφοράς ασύρματης ευρυζωνικής κίνησης. Στο πρώτο κεφάλαιο γίνεται μια σύντομη επισκόπηση των ευρυζωνικών δικτύων ασύρματης πρόσβασης καθώς και των χαρακτηριστικών τους. Στη συνέχεια αναφέρονται συνοπτικά τα σημαντικότερα θέματα που αφορούν τις τεχνικές της διαχείρισης πόρων σε τέτοιου είδους δίκτυα. Τέλος παρουσιάζονται οι επικρατέστερες εναλλακτικές τεχνολογίες που έχουν προταθεί για την μεταφορά ασύρματης ευρυζωνικής κίνησης. Στο δεύτερο κεφάλαιο περιγράφεται το μοντέλου ενός τυπικού ασύρματου ευρυζωνικού δικτύου και γίνεται μια εκτενής ανασκόπηση των επικρατέστερων τεχνικών διαχείρισης πόρων που έχουν προταθεί στην διεθνή βιβλιογραφία. Στη συνέχεια παρουσιάζονται αναλυτικά οι προτεινόμενες τεχνικές διαχείρισης πόρων καθώς και τα συγκριτικά αποτελέσματα της προσομοίωσης των μεθόδων αυτών σε σχέση με την αποδοτικότερη από τις υπάρχουσες τεχνικές. Τέλος συνοψίζονται τα συμπεράσματα που προέκυψαν από την εφαρμογή των προταθέντων τεχνικών. Στο τρίτο κεφάλαιο αρχικά παρουσιάζεται αναλυτικά το μοντέλο ενός συστήματος μεταφοράς ασύρματης ευρυζωνικής κίνησης μέσω επίγειας ασύρματης οπτικής ζεύξης. Στη συνέχεια μελετάται και αξιολογείται η απόδοση του εν λόγω συστήματος, χρησιμοποιώντας ως μετρικές την μέση πιθανότητα διακοπής καθώς και τη μέση πιθανότητα σφάλματος οι οποίες υπολογίζονται σε κλειστή μορφή. Τέλος παρουσιάζονται τα αριθμητικά αποτελέσματα της προσομοίωσης και παρατίθενται τα σχετικά συμπεράσματα. Στα πλαίσια του τέταρτου κεφαλαίου γίνεται η παρουσίαση της προτεινόμενης αρχιτεκτονικής ενός πολύ-αλματικού δικτύου εναέριων πλατφορμών μεγάλου ύψους οι οποίες διασυνδέονται με ασύρματη οπτική ζεύξη, με σκοπό την μεταφορά ασύρματης ευρυζωνικής κίνησης σε μεγάλες αποστάσεις. Εξετάζεται τόσο το σενάριο τους ενός όσο και το σενάριο των πολλών αλμάτων, και μελετάται η απόδοση ενός τέτοιου συστήματος όσον αφορά την μέση πιθανότητα διακοπής στον τελικό χρήστη. Στο τέλος του κεφαλαίου παρατίθενται τα αριθμητικά αποτελέσματα της προσομοίωσης καθώς και τα σχετικά συμπεράσματα. Τέλος, στο κεφάλαιο 5 συνοψίζονται τα σημαντικότερα συμπεράσματα που προέκυψαν από την παρούσα διατριβή και γίνονται υποδείξεις για περαιτέρω έρευνα.The present thesis aims to study resource allocation techniques in fixed broadband wireless networks in order to optimize their spectral efficiency as well as to investigate alternative broadband transfer methods. The first chapter gives a brief overview of broadband wireless access networks with their characteristics. The fundamental resource management techniques proposed in the open technical literature are also referred. Finally, the prevailing broadband transfer technologies are presented. The second chapter describes a typical wireless broadband network model and provides a comprehensive review of the key resource management techniques proposed in the literature. Then, the proposed resource management techniques are presented and compared using proper simulation results. Finally, conclusions are summarized. In the third chapter, the analytical model of a wireless broadband traffic model over a terrestrial wireless optical link is analyzed. Its performance is extracted using analytical expressions of the average outage probability and the average error probability metrics. Appropriate simulation results are depicted as well. In the fourth chapter, a network architecture comprising of several high amplitude platforms communicating with each other using optical links, is introduced in order to transfer broadband traffic over long distances. The outage probability performance is examined using either one-hop or multi-hop scenarios and suitable numerical results are provided. Finally, in chapter 5, concluding remarks are summarized and suggestions for further research are indicated

Contributions to channel modelling and performance estimation of HAPS-based communication systems regarding IEEE Std 802.16TM

New and future telecommunication networks are and will be broadband type. The existing terrestrial and space radio communication infrastructures might be supplemented by new wireless networks that make and will make use of aeronautics-technology. Our study/contribution is referring to radio communications based on radio stations aboard a stratospheric platform named, by ITU-R, HAPS (High Altitude Platform Station). These new networks have been proposed as an alternative technology within the ITU framework to provide various narrow/broadband communication services. With the possibility of having a payload for Telecommunications in an aircraft or a balloon (HAPS), it can be carried out radio communications to provide backbone connections on ground and to access to broadband points for ground terminals. The latest implies a complex radio network planning. Therefore, the radio coverage analysis at outdoors and indoors becomes an important issue on the design of new radio systems. In this doctoral thesis, the contribution is related to the HAPS application for terrestrial fixed broadband communications. HAPS was hypothesised as a quasi-static platform with height above ground at the so-called stratospheric layer. Latter contribution was fulfilled by approaching via simulations the outdoor-indoor coverage with a simple efficient computational model at downlink mode. This work was assessing the ITU-R recommendations at bands recognised for the HAPS-based networks. It was contemplated the possibility of operating around 2 GHz (1820 MHz, specifically) because this band is recognised as an alternative for HAPS networks that can provide IMT-2000 and IMT-Advanced services. The global broadband radio communication model was composed of three parts: transmitter, channel, and receiver. The transmitter and receiver parts were based on the specifications of the IEEE Std 802.16TM-2009 (with its respective digital transmission techniques for a robust-reliable link), and the channel was subjected to the analysis of radio modelling at the level of HAPS and terrestrial (outdoors plus indoors) parts. For the channel modelling was used the two-state characterisation (physical situations associated with the transmitted/received signals), the state-oriented channel modelling. One of the channel-state contemplated the environmental transmission situation defined by a direct path between transmitter and receiver, and the remaining one regarded the conditions of shadowing. These states were dependent on the elevation angle related to the ray-tracing analysis: within the propagation environment, it was considered that a representative portion of the total energy of the signal was received by a direct or diffracted wave, and the remaining power signal was coming by a specular wave, to last-mentioned waves (rays) were added the scattered and random rays that constituted the diffuse wave. At indoors case, the variations of the transmitted signal were also considering the following matters additionally: the building penetration, construction material, angle of incidence, floor height, position of terminal in the room, and indoor fading; also, these indoors radiocommunications presented different type of paths to reach the receiver: obscured LOS, no LOS (NLOS), and hard NLOS. The evaluation of the feasible performance for the HAPS-to-ground terminal was accomplished by means of thorough simulations. The outcomes of the experiment were presented in terms of BER vs. Eb/N0 plotting, getting significant positive conclusions for these kind of system as access network technology based on HAPS