Borrowing the idea and success of the Internet, we also architect IOTEdge chain to be two-levels: the local level chain, we call it L-chain, would be based on Tangle but an improved one, so-called LST-Tangle (explained later), just like the Local Area Network (Layer 2) in the Internet architecture; and the global level chain, we call it G-chain, would be based on Ethereum, just like the IP Protocol (Layer 3) in the Internet architecture. G-chain and L-chain are not two independent separate parts but two interacting subcomponents of one integral chain. L-Chain is essentially a short-term running ledger which records the detailed micro-transactions among its neighborhood only for a period of time, called T. This time period T is adjustable given different design, e.g. one hour, one day or one week etc. After every time period T, a consolidated version of the L-Chain ledger for the last T period will be put into G-Chain, just as a regular macro transaction, validated with consensus algorithm and becoming part of a block in G-Chain. With this design, we are able to keep the short-term ledger (L-Chain) with a constant storage footprint, while at the same time achieving a global consensus and permanent ledger with macro transactions at the G-Chain.