IST-2000-30148 I-METRA: D6.2 Implications in re-configurable systems beyond 3G (Part 2)

This activity evaluates the extension of the bandwidth of the UTRA MIMO HSDPA concept to 20 MHz, which is precisely the bandwidth of HIPERLAN/2. This would allow a fair comparison between the performance of UTRA MIMO HSDPA and the enhanced HIPERLAN/2. The bandwidth expansion would be the consequence of multiplying the chip rate of the W-CDMA spreading by four, i.e., 3.84 x 4 = 15.36 Mcps. A higher bandwidth MIMO channel model is necessary and this will be developed based on the channel model already developed in WP2. High data rates are required to satisfy the ever-increasing application requirements in future wireless communication systems. Recent investigations have indicated that a peak data rate of up to 20Mbps per user in the DL may be required for satisfactory reception of bursty traffic. As the transmission powers (of both mobile terminals and base stations) are limited, higher data rates lead to the reduction of the effective coverage area of a cell. That is, only users that are close to the base station will be able to communicate with high data rates, while users far away from the base station will only be able to use low data rates.Preprin

Dynamic Relaying in 3GPP LTE-Advanced Networks

Relaying is one of the proposed technologies for LTE-Advanced networks. In order to enable a flexible and reliable relaying support, the currently adopted architectural structure of LTE networks has to be modified. In this paper, we extend the LTE architecture to enable dynamic relaying, while maintaining backward compatibility with LTE Release 8 user equipments, and without limiting the flexibility and reliability expected from relaying. With dynamic relaying, relays can be associated with base stations on a need basis rather than in a fixed manner which is based only on initial radio planning. Proposals are also given on how to further improve a relay enhanced LTE network by enabling multiple interfaces between the relay nodes and their controlling base stations, which can possibly be based on technologies different from LTE, so that load balancing can be realized. This load balancing can be either between different base stations or even between different networks

On Integrated Access and Backhaul Networks: Current Status and Potentials

In this paper, we introduce and study the potentials and challenges of integrated access and backhaul (IAB) as one of the promising techniques for evolving 5G networks. We study IAB networks from different perspectives. We summarize the recent Rel-16 as well as the upcoming Rel-17 3GPP discussions on IAB, and highlight the main IAB-specific agreements on different protocol layers. Also, concentrating on millimeter wave-based communications, we evaluate the performance of IAB networks in both dense and suburban areas. Using a finite stochastic geometry model, with random distributions of IAB nodes as well as user equipments (UEs) in a finite region, we study the service coverage rate defined as the probability of the event that the UEs' minimum rate requirements are satisfied. We present comparisons between IAB and hybrid IAB/fiber-backhauled networks where a part or all of the small base stations are fiber-connected. Finally, we study the robustness of IAB networks to weather and various deployment conditions and verify their effects, such as blockage, tree foliage, rain as well as antenna height/gain on the coverage rate of IAB setups, as the key differences between the fiber-connected and IAB networks. As we show, IAB is an attractive approach to enable the network densification required by 5G and beyond.Comment: Revised manuscript in IEEE Open Journal of the Communications Societ

Quality of Packet Services in UMTS and Heterogeneous Networks OBJECTIVE AND SUBJECTIVE EVALUATION

In this thesis, the performance investigation of packet services in both a stan-dalone UMTS network and a UMTS network coexisting with other networks is undertaken. The investigations are concerned with the performance of a sin-gle link. Apart from objective performance metrics such as goodput and delay, subjective measures of user perceived QoS are also used. A real time emula-tion platform that uses a combination of simulated and real network protocols has been developed to enable both subjective and objective investigations from the user’s perspective. With regard to a standalone UMTS network, detailed emulation results are given concerning the performance enhancements due to the several mecha-nisms that control UMTS link layer retransmissions. The results show that the maximum number of retransmissions is the most determinant factor, and setting it to three or more eliminates TCP retransmissions and gives optimal performance (up to 85 % improvement in the goodput). The impact of TC