1to correspond (by letter, email etc)
2to send or receive messages through telecommunications
Examples
jǐn guǎn尽管jù lí距离hěn很yuǎn远，wǒ men我们hái shi还是bǎo chí保持zhe着tōng xìn通信lián xì联系。
尽管距离很远，我们还是保持着通信联系。
Even though we are far apart, we still keep in touch.
日本的第三代通信方式有W-CDMA和CDMA2000。
The third generation Japanese communication methods are W-CDMA and CDMA2000.