Self-optimized Coverage Coordination in Femtocell Networks

This paper proposes a self-optimized coverage coordination scheme for two-tier femtocell networks, in which a femtocell base station adjusts the transmit power based on the statistics of the signal and the interference power that is measured at a femtocell downlink. Furthermore, an analytic expression is derived for the coverage leakage probability that a femtocell coverage area leaks into an outdoor macrocell. The coverage analysis is verified by simulation, which shows that the proposed scheme provides sufficient indoor femtocell coverage and that the femtocell coverage does not leak into an outdoor macrocell.Comment: 16 pages, 5 figure

Proposed Multi-Mode Home Node-B Air Interface Protocol Stack Architecture

A Multi-mode Home NodeB (MHNB) is a system that can offer cellular service(s) to more than one different generation technology. The Universal Mobile Telecommunication System (UMTS) technology using NodeB as its transceiver station was developed to offer a high frequency range of 5MHz and because of this, the signal from the NodeB dilutes faster once reaching indoor. Studies showed that the idea of Home NodeB system by Third Generation Partnership Project (3GPP) came as a means to boost the diluted indoor signals. The challenge with this system is that it can only accommodate small number of subscribers as its Close Subscriber Group (CSG) without allowance for expansion. This study seeks to address the small capacity issue of the existing HNB by proposing a system that will accommodate wider capacity range and also, modify its operation from a single network mode to a Multi network mode technology. This will also offer great benefit to developing countries through extension of their GSM coverage and will also create a uniform platform for all cellular generation technologies. Keywords: Home NodeB, Multi-mode Home NodeB, Third Generation Partnership Project and Close Subscriber Group                                                                                                                        

Channel Capacity Maximization using NQHN Approach at Heterogeneous Network

In present scenario, the high speed data transmission services has pushed limits for wireless communication network capacity, at same time multimedia transmission in real-time needs provision of QoS, therefore the network capacity and small cell coverage has comes with lots of challenges. Improving the channel capacity and coverage area within the available bandwidth is necessary to provide better QoS to users, and improved channel capacity for the FCUs and MCUs in network. In this paper, we are proposing an NQHN approach that incorporate with efficient power allocation, improving the channel capacity by optimized traffic scheduling process in a small cell HetNets scenario. This work efficiently handle the interference with maintaining the user QoS and the implemented power controller uses HeNB power as per the real time based approach for macro-cell and femto-cell. Moreover, we consider the real traffic scenario to check the performance of our proposed approach with respect to existing algorith

Low energy indoor network : deployment optimisation

This article considers what the minimum energy indoor access point deployment is in order to achieve a certain downlink quality-of-service. The article investigates two conventional multiple-access technologies, namely: LTE-femtocells and 802.11n Wi-Fi. This is done in a dynamic multi-user and multi-cell interference network. Our baseline results are reinforced by novel theoretical expressions. Furthermore, the work underlines the importance of considering optimisation when accounting for the capacity saturation of realistic modulation and coding schemes. The results in this article show that optimising the location of access points both within a building and within the individual rooms is critical to minimise the energy consumption

INTERFERENCE MITIGATION PADA JARINGAN FEMTOCELL DENGAN PENYESUAIAN DAYA DAN BANDWIDTH MELALUI SKEMA SELF-CONFIGURATION

Seiring berkembangnya teknologi, komunikasi jarak jauh bukan lagi suatu hal yang eksklusif, kebutuhan akan komunikasi semakin tinggi, termasuk untuk di area indoor building. Permasalahan cukup besar yang dialami saat ini adalah sinyal dari BTS menurun drastis karena terhalang dinding dan beton, sehingga diperlukan adanya femtocell untuk menjaga kualitas sinyal. Salah satu permasalahan yang ditemui dalam penggunaan femtocell itu sendiri adalah munculnya interferensi yang dialami oleh pengguna yang berada pada jangkauan langsung BTS macro, yang dikenal dengan interferensi cross-tier. Permasalahan berikutnya yang muncul dari interferensi tersebut adalah tidak meratanya throughput yang diterima oleh pengguna femtocell. Salah satu skema untuk memaksimalkan kembali kualitas sinyal yang diterima oleh pengguna indoor building atas permasalahan interferensi jenis tersebut adalah dengan skema self-configuration. Siterapkannya sistem reward dan penalty pada skema tersebut, throughput yang didapatkan oleh setiap pengguna akan terus dipantau, sehingga pada akhirnya mendapat throughput diatas nilai yang diinginkan dengan tidak terlalu berlebih. Hasil yang didapatkan pada Tugas Akhir ini, skema self-configuration berhasil menaikkan throughput pengguna yang diobservasi pada saat dibawah nilai yang diinginkan, dan menurunkan throughput yang terlalu berlebih pada seluruh skenario bandwidth yang diujikan. Skema self-configuration dengan bandwidth 10MHz menjadi yang paling efektif jika dibandingkan dengan penggunaan dua bandwidth lainnya, dengan hasil saat throughput awal kurang dari 2Mbps, throughput meningkat 6.364 kali. Sedangkan ketika throughput awal lebih dari 2Mbps+Uf, throughput diturunkan 1.136 kali

Open, Closed, and Shared Access Femtocells in the Downlink

A fundamental choice in femtocell deployments is the set of users which are allowed to access each femtocell. Closed access restricts the set to specifically registered users, while open access allows any mobile subscriber to use any femtocell. Which one is preferable depends strongly on the distance between the macrocell base station (MBS) and femtocell. The main results of the paper are lemmas which provide expressions for the SINR distribution for various zones within a cell as a function of this MBS-femto distance. The average sum throughput (or any other SINR-based metric) of home users and cellular users under open and closed access can be readily determined from these expressions. We show that unlike in the uplink, the interests of home and cellular users are in conflict, with home users preferring closed access and cellular users preferring open access. The conflict is most pronounced for femtocells near the cell edge, when there are many cellular users and fewer femtocells. To mitigate this conflict, we propose a middle way which we term shared access in which femtocells allocate an adjustable number of time-slots between home and cellular users such that a specified minimum rate for each can be achieved. The optimal such sharing fraction is derived. Analysis shows that shared access achieves at least the overall throughput of open access while also satisfying rate requirements, while closed access fails for cellular users and open access fails for the home user.Comment: 26 pages, 8 figures, Submitted to IEEE Transactions on Wireless Communication

Resource management for macrocell users in hybrid access femtocells

Abstract-The constant evolution of mobile-phone traffic demands for novel networking solutions especially focused on indoor environment. In this context, the use of femtocells, i.e., cells with very limited coverage area, has been proposed. In this paper, a femtocell network with hybrid access control mode is considered. The activity profile of the Femtocell Users (FUs) is modeled to compute the maximum achievable throughput and the consumed energy per successfully transmitted data bit by the Macrocell Users (MUs), depending on which set of channels are operated in open access mode, i.e., which channels can be used by MUs. Thus, it is identified how many and which channels must be operated in open access mode, depending on the physical capacities of the channels and the amount of time these channels are not occupied by FUs. The results motivate the need for novel resource management schemes which can dynamically adapt the set of open access channels to the network conditions