This paper deals with development of offset microstrip line fed patch antenna to operate at resonant frequency of 4.9 GHz for public safety WLAN video surveillance services. The patch of suggested antenna looks like C shaped stub attached to offset microstrip feed line and the ground is etched with two rectangular slots. These two rectangular slots of dimensions 12.25 mm × 1.75 mm and 17 mm × 1.75 mm are observed to enhance the gain. All the simulations are carried out by HFSS. Initially the design evolution of the developed antenna started with traditional rectangular shaped patch antenna. To make the patch effective with respect to current distribution, rectangular patch is converted as a ring with offset microstrip line feed. Improvement in the reflection coefficient at desired frequency is obtained by separating the two strips of rectangular loop and optimizing their measurements as 25 mm × 1.5 mm and 17 mm × 3.5 mm. The developed antenna resonates at 4.93 GHz covering 132 MHz bandwidth with reflection coefficient of -24.89 dB. The simulated maximum gain is 3.8 dB which is improved from -17.19 dB. The change in resonant frequency can be obtained by offsetting the feed. Prototype antenna material is FR-4 of permittivity value 4.4 and overall dimensions of 60 mm × 60 mm. Experimental and software tested results exhibits good concurrence. The proposed design shows improved gain and better reflection coefficient compared to conventional geometry.