摘要：In low-duty-cycle wireless sensor networks,designers have to cope with unreliable links and limited communication *** this work,we propose COST,a coding scheme that leverages spatial-temporal diversity to achieve higher energy efficiency and lower delay of packet *** particularly address long sleeping intervals in low-duty-cycle networks by exploiting multi-path ***,we propose to employ an erasure-coding scheme to improve *** respect to energy efficiency and delivery timeliness,we formulate the problem in optimal allocation of coded blocks over multiple paths,which is then proved to be *** further propose a near-optimal algorithm to solve the allocation *** extensive simulations,we evaluate the impact of network parameters and demonstrate the effectiveness of our proposal.