Single Wire Protocol

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The Single Wire Protocol (SWP) is a specification for a single-wire connection between the SIM card and a near field communication (NFC) chip in a cell phone. It is currently under final review by the European Telecommunications Standards Institute (ETSI).[1][2]

SWP is an interface between Contactless frontend (CLF) and UICC (SIM card chip). It is a contact based protocol which is used for contactless communication. C6 pin of UICC is connected to CLF for SWP support. It is a bit oriented full duplex protocol i.e. at the same time transmission as well as reception is possible. CLF acts as a master and UICC as a slave. CLF provides the UICC with energy, a transmission clock, data and signal for bus management. The data to be transmitted are represented by the binary states of voltage and current on the single wire.

See also[edit]


  1. ETSI SCP Activity Report 2007.[3]
  2. The Register, The future of the SIM hangs by a single Wire 2008.[4]
  3. GSM Association: Requirements For SWP NFC Handsets V2 2008.[5]
  4. Fast Company: Nokia's 2011 Smartphones Have Built-In Wireless Payment Tech: Take That, Apple![6]


  1. ^ ETSI TS 102 613 V.11.0.0 - UICC-CLF Interface; Part 1: Physical and data link layer characteristics (Release 11)
  2. ^ ETSI TS 102 622 V.12.1.0 - UICC-CLF Interface; Host Controller Interface (HCI) (Release 12)
  3. ^
  4. ^
  5. ^
  6. ^