UMTS Services aspects

UMTS services are based on common capabilities throughout all UMTS user and radio environment. The purposes of UMTS are:

• Enabling users to access a wide range of telecommunications services, including many that are today undefined as well as multimedia and high data rates.
• Allowing the difference between service offering of various serving networks and home environments.
• Providing support for interfaces which allow the use of terminals normally connected to fixed networks.
  
• Facilitating the provision of small, easy to use, low cost terminal with long talk time and long standby operation.
• Providing an efficient means of using networks (specially spectrum).

Based on above objectives, specific requirement related to services are outlined in the ETSI specifications. Data rates offered for bearer services are:

• 144 kbits/s for satellite and rural outdoor
• 384 kbits/s for urban outdoor
• 2048 kbits/s for indoor and low range outdoor
  

UMTS network services have different QoS classes for four types of traffic:

• Conversational (voice, video telephony, video gaming) This is characterized by low delay tolerance, low jitter (delay variation) and low error tolerance. The data rate requirement may be high or low, but is generally symmetrical.
• Streaming (multimedia, video on demand, webcast) This concerns one-way services, using low- to high-bit rates. Streaming services have a low-error tolerance, but generally have a high tolerance for delay and jitter. That is because the receiving application usually buffers data so that it can be played to the user in a synchronized manner.
• Interactive (web browsing, network gaming, database access) This consists of typically request/response-type transactions. Interactive traffic is characterized by low tolerance for errors, but with a larger tolerance for delays than conversational services. Jitter (delay variation) is not a major impediment to interactive services, provided that the overall delay does not become excessive.
• Background (email, SMS, downloading) This is characterized by little, if any, delay constraint.