frequency 3.35 GHz) and 16.52% (at center frequency 3.57 GHz) in the broadside direction (h 5 08, U 5 08) shown in Figure 7. It is observed that in the Figure 8 the RHCP is stronger than the left hand circular polarization (LHCP) in broadside direction so, the proposed antenna is called RHCP. The simulated and measured RHCP and LHCP radiation patterns in xz-and yz-plane at 3.35, 3.55, and 3.75 GHz are shown in Figure 8. It has been found that in broadside direction the RHCP leads the LHCP by 226.63 dB, 219.28 dB, and 226.05 dB at 3.35 GHz, 3.55 GHz, and 3.75 GHz, respectively. The electric field distribution observed inside the DRA at different phase, that is, 08, 908, 1808, and 2708 confirms the proposed design is CP and it also confirms that the mode of DRA is TE 12d mode shown in Figure 9. The average gain and radiation efficiency is 4.69 dB and 74.84% in the working band shown in Figure 10. Table 1 show the comparison of earlier published work. It has been observed that proposed work shows improvement in AR bandwidth within working band over earlier reported design. CONCLUSIONIn this article, a new modified microstrip-line-fed rectangular dielectric resonator antenna coupled with slotted ground plane for circular polarization has been proposed. The measured impedance bandwidth is 17.87% (at center frequency 3.58 GHz) and measured AR bandwidth of proposed antenna is 16.52% (at center frequency 3.57 GHz) in the broadside direction (h 5 08, U 5 08), respectively. The proposed dielectric resonator antenna offer simple construction with sufficient bandwidth and excellent far-field properties. TE 12d mode has been excited in this proposed antenna. It has been observed that the proposed antenna shows RHCP in broadside direction (h 5 08, U 5 08). This antenna can be suitable for Wi-MAX (3.3-3.6 GHz) applications.

If the mobile station requests the channel allocation in mobile networks, switching center is assigned a channel to mobile station that belong to each base station. Channel allocation schemes is a fixed channel allocation, dynamic channel allocation and a hybrid approach that combines the two forms. To assign a frequency well to use resources efficiently to provide quality service to our customers. In this paper, we proposed method to assign frequencies to minimize interference between channels and to minimizes the number of searching time. The proposed method by the genetic algorithm to improve accuracy and efficiency of the verification steps and reproduction stages were used. In addition, the proposed method by comparing with other methods showed that proposed method is better through the simulations.

As the spread of smart devices that service variety of content, limited mobile terminal channel assignment problem has intensified. In the channel assignment in mobile networks mobile switching center at the request belongs to each base station allocates the channel to the mobile station. This effectively allocate the limited channels of various methods have been proposed for, in this case a hybrid channel allocation using genetic algorithms UHGA (Universal Hybrid Channel Assignment using Genetic Algorithm) in rural areas or urban areas, such as universal network applied to a variety of environments that the efficiency is verified through simulation.