Cordless phones connect to the wired phone network through a "base station" - the part which is plugged into the phone jack. The base station and cordless phone handset communicate by radio.
The handset only transmits during a call. The base station, however, sends out very brief transmissions periodically even when there is there is no call in progress, in order to maintain contact with the handsets that are connected to it. The average power is very low.
The graph below shows measurements made at distances of 0.3, 0.5 and 1 metre from a Panasonic DECT cordless phone with no call in progress. Measurements were made at the front, left and right of the phone, and the results are shown in the graph. The graph shows the exposure as a percentage of the public limit in the New Zealand exposure Standard.
30 centimetres from the phone, the highest exposure on any side (the right side, as you look at the phone) was 0.016% of the limit (ie about 6,000 times below the limit). One metre away the highest exposure was less than one tenth of this.
When the base station was mounted onto a wall, the exposure on the other side of the wall about 30 cm from the rear of the base station was 0.0016% of the public limit.