This paper considers the problem of data collection in a sensor network using network coding (NC). It proposes a decoding approach, called HAND, which does not require source packets to be supplemented with NC headers (with encoding vectors), classically used to decode the network-coded packets. HAND exploits the structure imposed by the communication protocol on the packet headers to estimate the original source packets from the received network-coded packets. Network-decoded packets are obtained as the solution of systems of linear equations. The decoding complexity is only one order of magnitude larger than that of classical network decoding.