Redline Communications Inc. AN100UXA Manual Do Utilizador
User
AN-100U/UX Base Station
Manual
70-00058-01-04
Proprietary Redline Communications © 2010
Page 105 of 136
April 19, 2010
For example, the Min. Reserved Rate of 409,600 bps has a quantum (Q) of 512 bytes. If
an application using this connection sends a 1500 byte packet, the packet will not be
transmitted immediately, because the initial deficit counter value (Q = 512) will be less
than the packet size. The deficit counter will accumulate to 1536 on the 3rd wireless
frame (3 x 512 = 1536) and the packet may be transmitted (based on priority and
available bandwidth). After the packet is transmitted, the updated deficit counter will be
1536 - 1500 = 36.
an application using this connection sends a 1500 byte packet, the packet will not be
transmitted immediately, because the initial deficit counter value (Q = 512) will be less
than the packet size. The deficit counter will accumulate to 1536 on the 3rd wireless
frame (3 x 512 = 1536) and the packet may be transmitted (based on priority and
available bandwidth). After the packet is transmitted, the updated deficit counter will be
1536 - 1500 = 36.
The following table lists some throughput rates and the associated Q size.
Min. Reserved Rate = Q * 8 / Frame Duration
Table 52: Sample Quantum (Q) Values ( 10 ms Frame)
Quantum Q (Bytes) *
Min. Sustained Rate (bps)
3 160
2 528 000
1 518
1 214 400
1 280
1 024 000
512
409 600
256
204 800
128
102 400
64
51 200
6.4
Connection Types
User traffic is transmitted only over connections (service flows). Each connection
represents a unidirectional data flow between the base station and subscriber. Downlink
connections control traffic from the base station to the subscriber and uplink in the
opposite direction.
represents a unidirectional data flow between the base station and subscriber. Downlink
connections control traffic from the base station to the subscriber and uplink in the
opposite direction.
Each connection type has unique characteristics applicable to transporting specific types
of user traffic across the wireless interface. Connections may be assigned individual
Quality of Service (QoS) settings including priority, throughput rates, and maximum
latency. The following sections describe each connection type and the associated
scheduling requirements.
of user traffic across the wireless interface. Connections may be assigned individual
Quality of Service (QoS) settings including priority, throughput rates, and maximum
latency. The following sections describe each connection type and the associated
scheduling requirements.
6.4.1 UGS - Unsolicited Grant Service
The UGS service has the highest priority after management traffic and has the lowest
latency and jitter. This service is designed for real-time applications sending fixed size
packets at a constant rate. Typical applications include VoIP without silence
suppression, legacy TDM, or fixed-rate video. The UGS service reserves a fixed-size
bandwidth allocation in every scheduled wireless frame.
latency and jitter. This service is designed for real-time applications sending fixed size
packets at a constant rate. Typical applications include VoIP without silence
suppression, legacy TDM, or fixed-rate video. The UGS service reserves a fixed-size
bandwidth allocation in every scheduled wireless frame.
Important: The Max. Reserved Rate should be based on a calculation that enumerates
the number of packets to be included in a wireless frame. A simple estimate based only
on minimum bandwidth may not provide optimum use of the reserved bandwidth (see
examples following).
the number of packets to be included in a wireless frame. A simple estimate based only
on minimum bandwidth may not provide optimum use of the reserved bandwidth (see
examples following).
Downlink Connections
Max. Sustained Rate: Specify the required minimum bandwidth to reserve in every
wireless frame. Allocation is based on queued packets and unused downlink bandwidth
is available for use by other connections or services. Downlink UGS traffic is reserved in
every wireless frame (Max. Latency setting is ignored).
wireless frame. Allocation is based on queued packets and unused downlink bandwidth
is available for use by other connections or services. Downlink UGS traffic is reserved in
every wireless frame (Max. Latency setting is ignored).
For example, an application is sending 400 x 610 byte packets each second in the
downlink direction. The downlink UGS service flow reserves bandwidth in every wireless
frame.
downlink direction. The downlink UGS service flow reserves bandwidth in every wireless
frame.
Max. Sustained Rate = 400 x 692 * 8 + 5% = 2,325,120 bps