In this work we consider nano-scale communication using bacterial popula- tions as transceivers. We demonstrate using a microfluidic test-bed and a population of genetically engineered Escherichia coli bacteria serving as the communication re- ceiver that a simple modulation like on-off keying (OOK) is indeed achievable, but suffers from very poor data-rates. We explore an alternative communication strategy called time elapse communication (TEC) that uses the time period between signals to encode information. We identify the severe limitations of TEC under practical non-zero error conditions in the target environment, and propose an advanced communication strategy called smart time elapse communication (TEC-SMART) that achieves over a 10x improvement in data-rate over OOK.