Contents 15.1 Motivation: e Need for a New Architecture ........................................394 15.2 Limitations of Existing P2P Architectures ..............................................397 15.2.1 Unstructured ..............................................................................397 15.2.2 Structured ..................................................................................399 15.2.3 Hybrid ...................................................................................... 400 15.2.4 Super-Peer ..................................................................................402 15.3 Proposed Wi-Fi ESPA .............................................................................402 15.3.1 Application/Interface Layer ........................................................403 15.3.2 QoS Layer ..................................................................................403 15.3.3 Search Layer ...............................................................................405 15.4 Mobile Authentication and Resource eXchange Protocol ....................... 406 15.4.1 Protocol Overview and Semantics ..............................................407 15.4.2 MARX Protocol Operations ..................................................... 408 15.4.2.1 Registration ............................................................... 409 15.4.2.2 Peer Authentication ....................................................410 15.4.2.3 Data Retrieval ............................................................412 15.5 Replication of LISSP Data ...................................................................... 415 15.6 Path Selection .........................................................................................418 15.7 Security ...................................................................................................419