User's Manual

26 MDS Mercury 16E Technical Manual MDS 05-6302A01, Rev. A
Service Types WiMAX provides five types of service: Unsolicited Grant Service
(UGS), Real-time Polling Service (RTPS), Non-real time polling
Service (nRTPS), Enhanced Real-time Polling Service (eRTPS), and
Best Effort (BE). The characteristics and typical uses for service type
are given in Table 4 below.
Flow Parameters
There are several parameters to be specified when creating a service
flow. Table 5 shows which service flow parameters apply to each type
of service.
Table 4. Service Types and Characteristics
Service Type Characteristics Typical Uses
Unsolicited Grant
Service (UGS)
The BS grants bandwidth to the SU without
it needing to make a request. The
bandwidth is always allocated.
Real time applications generating fixed-size
packets on a periodic basis and requiring low
latency and jitter, such as VoIP.
Real-time Polling
Service (RTPS)
The BS provides specific bandwidth
request opportunities for the SU. This is
more efficient than UGS in not wasting
bandwidth but is less efficient in
request/grant of bandwidth.
Real time applications generating
variable-size packets on a periodic basis,
such as MPEG video.
Non-real time
polling Service
(nRTPS)
The BS polls the SU every one second or
less. The SU may use the polling requests
or contention requests. This is an efficient
request mechanism but does not provide
consistent bandwidth for data.
Delay-tolerant applications generating
variable-size packets on a periodic basis,
such as an FTP transfer.
Enhanced
Real-time Polling
Service (eRTPS)
Combination of UGS and RTPS in which
the BS provides bandwidth grants as in
UGS but the Subscriber can adjust the size
of the grants in order to not waste
bandwidth.
Real time applications generating
variable-size packets on a periodic basis,
such as VoIP with silence suppression.
Best Effort (BE) The Subscriber uses contention request
opportunities to request bandwidth for
data. Bandwidth is provided on a best effort
basis with no acknowledgement.
Non-real time, non-critical applications and
data flows such as web browsing.
Table 5. Flow Parameters
Parameter UGS RTPS nRTPS eRTPS BE
Min Reserved Rate (Y) Y Y Y N
Max Sustained Rate YYY YN
Priority NY Y N
Max Latency YYN YN
Grant Interval YNN YN
Polling Interval NY Y NN