Traffic classes in 5G

• Before 5G, traffic classes (associated with QoS classes) considered were:
  1. Conversational: real time in both downlink (DL) and uplink (UL). Examples: telnet, network games, stock exchange, video-conferences, Voice over IP (VoIP)
  2. Streaming: real-time only for DL, almost no traffic in UL. Examples: audio and video-streaming
  3. Interactive: non-real time, traffic in both DL and UL. Typical example: WWW
  4. Background: non-real time traffic. Examples: e-mail or FTP. Sometimes FTP is considered in the streaming category.
  • The delay constraints increase (i.e, smaller delay required) from background to conversational traffic types
  • Reliability constraints increase from conversational to background.
• In 5G, all traffic classes considered before are included into the traffic class called eMBB (enhanced Multimedia Broadcast).
• New traffic classes (types) are considered:
  • URLLC (Ultra Reliable Low Latency Communications): has extreme constraints concerning the delay, i.e., can have end-to-end delay requirements less than 1 ms (millisecond).
    • Characterised by small amounts of data, but the data packets must have very small delay and extremely high reliability
    • Example: mission critical applications like tele-medicine, tele-robotics, etc; enhanced reality, tactile internet, autonomous driving, industry automation
    • Needs a scheduling cycle less than 1ms, maybe as low as 0.125 ms or even 0.1 ms
  • mMTC: massive Machine Type Communications: smart city or smart building, data generated by sensor networks
    • In general it is considered to contain big amounts of data, but delay is not critical
    • It is considered that it needs a schedluer with scheduling cycle bigger than 1 ms