What is the difference between VoLTE and VoWiFi?

ComparloCategory: TechnologyWhat is the difference between VoLTE and VoWiFi?
Ahmed Ibrahim asked 3 years ago

{“lhsI”:”VoLTE”,”rhsI”:”VoWiFi”}

1 Answers
Karim MRabie answered 3 years ago
[{“cellsNumber”:1,”row”:”Introduction”,”lhsI”:”VoLTE%2C%20Voice%20over%20LTE%26nbsp%3Band%20VoWiFi%2C%20Voice%20over%20WiFi%20are%20two%20of%20three%20%22common%22%20solutions%20for%20Voice%20handling%20in%20LTE.%3Cbr%20/%3E%3Cbr%20/%3EDue%20the%20nature%20of%20LTE/EPC%20Network%20as%20a%20completely%20All-IP%26nbsp%3BMobile%20Data%20Network%2C%20the%20two%26nbsp%3Bsolutions%20were%20standardised%20to%20deliver%20voice%20services%20in%20LTE%20%28e.g.%20Voice%20Calling%29%20in%20addition%20to%20the%20Solution%20of%20CSFB%20%28Circuit%20Switched%20Fallback%29.%3Cbr%20/%3E%3Cbr%20/%3EBelow%20is%20a%20high-level%20digram%20that%20illustrates%20the%20Voice%20handling%20in%20LTE.%3Cbr%20/%3E%3Cbr%20/%3E%3Cimg%20style%3D%22width%3A%20100%25%3B%20height%3A%20auto%3B%22%20src%3D%22../../wp/wp-content/plugins/custom-qa/images/blobid1488141177428.png%22%20alt%3D%22%22%20/%3E”,”rhsI”:”VoWiFi%2C%20Voice%20over%20WiFi%20is%20a%20term%20that%20describes%20the%20solution%20to%20deliver%26nbsp%3B%22Voice%22%20Services%20under%20WiFi%20Coverage%20with%20specific%20conditions.”},{“cellsNumber”:2,”row”:”Theory”,”lhsI”:”Voice%20over%20LTE%20is%20an%20IMS-based%20Solution%20that%20enables%20operators%20to%20migrate%20legacy%20Voice%20service%20to%20LTE%20Network%20in%20addition%20to%20the%20introduction%20of%20new%20Multimedia%20Services%20on%20LTE%20network.%20%3Cbr%20/%3E%3Cbr%20/%3EVoLTE%20relies%20on%20the%20concept%20of%20dedicated%20bearer%20is%20LTE%20where%20the%20LTE%20user%20is%20granted%20a%20average%20QoS%20default%20bearer%20whenever%20the%20handset%20is%20turned%20on%20%22Attached%22%20enabling%20the%20user%20to%20register%20for%20IMS%20Services%20%28IMS%3A%20IP%20Multimedia%20Subsytem%29%3Cbr%20/%3E%3Cbr%20/%3EWhenever%20the%20user%20initiates%20a%20call%20or%20receive%20a%20call%2C%20a%20dedicated%20bearer%20is%20triggered%20by%20the%20network%20with%20Voice-set%20quality%20of%20service%20this%20enabling%20the%20user%20to%20establish%20the%20call%20with%20the%20aid%20of%20EPC%20%28Evolved%20Packet%20Core%29%20and%20IMS.”,”rhsI”:”VoWiFi%20technology%20enables%20WiFi%20Calling%20for%20special%20capable%20handsets%20via%20the%20integration%20of%20Non%203GPP%20Access%20%28WiFi%29%20with%20the%20EPC%20%26amp%3B%20IMS%20Network.%20%3Cbr%20/%3E%3Cbr%20/%3ESimilar%20to%20VoLTE%2C%20VoWiFi%20relies%20on%20establishing%20a%20dedicated%20bearer%20for%20Voice%20Call%20maintaining.%20%3Cbr%20/%3E%3Cbr%20/%3EThe%20difference%20is%20that%20the%20VoWiFi%20terminal%20is%20connecting%20via%20Wirelss%20Network%20that%20can%20belong%20to%20a%20different%20ISP.%3Cbr%20/%3EAn%20IPSec%20Tunnel%20is%20established%26nbsp%3Bbetween%20the%20handset%20and%20a%20newly%20introduced%20Network%20Element%20called%20ePDG%20%28Evolved%20Packet%20Data%20Gateway%29%20which%20in%20turns%20integrate%20with%20the%20PGW%20of%20EPC.%3Cbr%20/%3E%3Cbr%20/%3EUpon%20IPSec%20Tunnel%20Creation%2C%20UE%20register%20in%20IMS%26nbsp%3Band%20follow%20the%20same%20VoLTE%20Call%20flow.”},{“cellsNumber”:2,”row”:”Why to adopt?”,”lhsI”:”Possible%20motivations%20for%20Mobile%20Operators%20can%20be%3Cbr%20/%3E%0A%3Cul%3E%0A%3Cli%3EEnhancing%20User%20Experience%20reducing%20time%20for%20call%20establishment%26nbsp%3B%3C/li%3E%0A%3Cli%3EPlan%20to%20migrate%20Services%20from%202G/3G%20to%204G%3C/li%3E%0A%3Cli%3E4G%20Green%20Field%20deployment%20%28No%20existing%202G/3G%20Network%29%3C/li%3E%0A%3Cli%3EMVNO%20Obligation%26nbsp%3Bto%20use%20only%204G%3C/li%3E%0A%3Cli%3EPlan%26nbsp%3Bto%20provide%20more%20advanced%20services%3C/li%3E%0A%3C/ul%3E”,”rhsI”:”Possible%20motivations%20for%20Mobile%20Operators%20can%20be%3Cbr%20/%3E%0A%3Cul%3E%0A%3Cli%3E%3Cspan%20style%3D%22font-family%3A%20Lato%2C%20sans-serif%3B%20font-size%3A%20small%3B%22%3EEnhancing%20the%20Radio%20Coverage%20in%20some%20specific%20areas.%20%3C/span%3E%3C/li%3E%0A%3Cli%3E%3Cspan%20style%3D%22font-family%3A%20Lato%2C%20sans-serif%3B%20font-size%3A%20small%3B%22%3EAttractive%20alternative%20solution%20for%20high%20cost%20roaming.%20%3C/span%3E%3C/li%3E%0A%3Cli%3E%3Cspan%20style%3D%22font-family%3A%20Lato%2C%20sans-serif%3B%20font-size%3A%20small%3B%22%3EMarketing%20Competition%3C/span%3E%3C/li%3E%0A%3C/ul%3E”},{“cellsNumber”:2,”row”:”References”,”lhsI”:”%3Cul%3E%0A%3Cli%3E3GPP%20TS%2023.401%20General%20Packet%20Radio%20Service%20%28GPRS%29%20enhancements%20for%20Evolved%20Universal%20Terrestrial%20Radio%20Access%20Network%20%28E-UTRAN%29%20access%26nbsp%3B%3C/li%3E%0A%3Cli%3E3GPP%20TS%2029.274%20Evolved%20General%20Packet%20Radio%20Service%20%28GPRS%29%20Tunnelling%20Protocol%20for%20Control%20plane%20%28GTPv2-C%29%3B%20Stage%203%26nbsp%3B%3C/li%3E%0A%3Cli%3E3GPP%20TS%2029.228%26nbsp%3BUniversal%20Mobile%20Telecommunications%20System%20%28UMTS%29%3B%20LTE%3B%26nbsp%3BIP%20Multimedia%20Subsystem%20%28IMS%29%3B%26nbsp%3BStage%202%3C/li%3E%0A%3C/ul%3E”,”rhsI”:”%3Cul%3E%0A%3Cli%3E%3Cspan%20style%3D%22font-family%3A%20Lato%2C%20sans-serif%3B%20font-size%3A%20small%3B%22%3E%26nbsp%3B%3C/span%3E3GPP%20TS%2023.402%26nbsp%3BArchitecture%20enhancements%20for%20non-3GPP%20accesses%26nbsp%3B%3C/li%3E%0A%3Cli%3E3GPP%20TS%2024.302%26nbsp%3BAccess%20to%20the%203GPP%20Evolved%20Packet%20Core%20%28EPC%29%20via%20non-3GPP%20access%20networks.%3C/li%3E%0A%3C/ul%3E”},{“cellsNumber”:2,”row”:”Potential Interview Questions”,”lhsI”:”%3Cul%3E%0A%3Cli%3E%3Cspan%20style%3D%22font-family%3A%20Lato%2C%20sans-serif%3B%20font-size%3A%20small%3B%22%3E%26nbsp%3B%3C/span%3EWhat%20is%20the%20difference%20between%20VoLTE%20and%20CSFB%3F%3C/li%3E%0A%3Cli%3EWhat%20is%20the%20difference%20between%20default%20bearer%20and%20dedicated%20bearer%3F%3C/li%3E%0A%3Cli%3EWhat%20is%20the%20call%20flow%20for%20for%20MO%20Call%3F%3C/li%3E%0A%3Cli%3EHow%20is%20VoLTE%20Call%20established%20for%20Roamers%3F%3C/li%3E%0A%3C/ul%3E”,”rhsI”:”%3Cul%3E%0A%3Cli%3E%3Cspan%20style%3D%22font-family%3A%20Lato%2C%20sans-serif%3B%20font-size%3A%20small%3B%22%3E%26nbsp%3B%3C/span%3EWhat%20is%20the%20function%20of%20ePDG%3F%3C/li%3E%0A%3Cli%3EHow%20does%20the%20UE%20Know%20the%20IP%20address%20of%20ePDG%3F%3C/li%3E%0A%3Cli%3EIs%20Handover%20possible%20between%20WiFi%20and%204G%3F%3C/li%3E%0A%3Cli%3EIn%20good%20WiFi%20%26amp%3B%204G%20Coverage%2C%20what%20will%20be%20the%20UE%20Network%20preference%3F%3C/li%3E%0A%3C/ul%3E”}]
Ahmed Ibrahim
replied 3 years ago

Thanks Karim for the great comparison.

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