 calculations specifically in EDGE are noted below. Incremental Redundancy Use of IR in coordination with LA not only makes re-transmission more efficient but also optimises the performance of the system. It reduces the required C/I by at least 3 dB. Link budgets are calculated for a given modulation and coding scheme for a specific BLER. The BLER value affects directly the gain due to IR. In fact, the higher the BLER, the higher the IR gain. Body Loss When a mobile comes near to the human body, the signal level goes down. This is known as body loss. In GSM 900, this loss is typically 3 dB. No body loss is taken into account for packet data services in an EDGE network. Diversity Effects Use of diversity schemes generally has a positive impact on link performance, thereby in- creasing the area covered by individual sites. Both uplink and downlink diversity schemes are possible. However, smart radio concepts can be used to increase the coverage perfor- mance of an EDGE network drastically. In uplink diversity, multiple antennas are used so as to cancel the correlated noise received at the antennas. Reduction of noise leads to a gain in the signal level. When there is no noise, the system allows the signal to flow without noise reduction. In the downlink direction, two transmitters are used and the signal is transmitted through two uncorrelated paths in bursts with slight delays. The transmitted power increases substantially with the use of two transmitters. Transmission of the signal over two different paths with delay reduces the effects of fast fading. Thus, the link performance and coverage can be increased substantially in EDGE radio networks as compared with GSM or GPRS radio networks. Received Signal Strength Signal strength in radio networks can be expressed in relation to interference signals. There are three parameters that specify this: Eb/No,Eg/No and C/N. Both Es/No and C/N can be expressed in terms of Eb/No, which is the ratio of available bit energy to the noise spectral density (also known as the sig