1. Wi-Fi Calling. http://www.cisco.com/c/en/us/solutions/collateral/service-provider/service-provider-wi-fi/white-paper-c11--733136.html. Wi-Fi Calling. http://www.cisco.com/c/en/us/solutions/collateral/service-provider/service-provider-wi-fi/white-paper-c11--733136.html.
2. 3GPP. 3GPP aSRVCC Working Item. http://www.3gpp.org/DynaReport/WiCr-500011.htm. 3GPP. 3GPP aSRVCC Working Item. http://www.3gpp.org/DynaReport/WiCr-500011.htm.
3. 3GPP. 3GPP.TS129.238 AMR-WB speech codec. http://www.etsi.org/deliver/etsi_ts/126200_126299/126204/12.00.00_60/ts_126204v120000p.pdf. 3GPP. 3GPP.TS129.238 AMR-WB speech codec. http://www.etsi.org/deliver/etsi_ts/126200_126299/126204/12.00.00_60/ts_126204v120000p.pdf.
4. 3GPP. 3GPP.TS129.238 TrGW. http://www.etsi.org/deliver/etsi_ts/129200_129299/129238/12.04.00_60/ts_129238v120400p.pdf. 3GPP. 3GPP.TS129.238 TrGW. http://www.etsi.org/deliver/etsi_ts/129200_129299/129238/12.04.00_60/ts_129238v120400p.pdf.
5. 3GPP. 3GPP.TS146 081 DTX for EFR speech traffic channels. http://www.etsi.org/deliver/etsi_ts/129200_129299/129238/12.04.00_60/ts_129238v120400p.pdf. 3GPP. 3GPP.TS146 081 DTX for EFR speech traffic channels. http://www.etsi.org/deliver/etsi_ts/129200_129299/129238/12.04.00_60/ts_129238v120400p.pdf.