This paper addresses the Co-Channel Interference (CCI) reduction in Relay Assisted (R-A) cellular systems using Beamforming (BF) techniques. Analytical treatments are conducted. The network performance improvements through reducing the CCI are evaluated using three different configurations of applying BF. These configurations represent Relay Station (RS) do BF only, Base Station (BS) do BF only and both RS and BS do BF. Additionally, the considered BF techniques denote the horizontal, vertical, and Three Dimensional (3D) BF techniques. Therefore, each configuration consists of three different scenarios. Accordingly, nine different scenarios are studied. A comparison of these scenarios is introduced to enhance the network Quality of Service (QoS). Moreover, closed-form expressions for worst-cases Cell Edge User’s (CEU’s) Signal to Interference Ratio (SIR), Cell Center User’s (CCU’s) SIR and inner radius are implemented. Furthermore, various performance evaluation metrics are used to compare the different scenarios. The results reveal, that the performance of vertical BF is close to that of the 3D BF in low Path-loss (PL) exponent range. Therefore, applying vertical BF is preferable from the network cost and power consumption perspectives. Furthermore, it is observed, that the configuration of RS do BF is superior to other configurations when horizontal or vertical BF technique is employed. Additionally, the configuration of both RS and BS do BF outperforms the other configurations when 3D BF is applied. However, as unexpected it performs worse than them when the other BF techniques are applied. The work outcomes attain much higher CEU’s SIR improvement. Therefore, the coverage probability is increased. Thus, more users can be served by the network. Accordingly, the total network cost is reduced. So, this treatment not only improves the network performance, but also it reduces the total network cost.