Single Wire Protocol

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 universal integrated circuit card (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 alsoEdit


  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. ^ "Template".
  4. ^ "The future of the SIM hangs by a single wire".
  5. ^[permanent dead link]
  6. ^