Redline Communications Inc. SUOA Manuale Utente

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 Red
MAX
 
Subscriber Modem
 
SU-O  User Manual
 
 
70-00057-01-01-DRAFT 
Proprietary Redline Communications © 2007 September 
7, 
2007 
Page 18 of 55
 
allows planners to obtain the maximum geographic coverage, while avoiding frequency 
contention in adjacent sectors. 
 
2.3 Service 
Flows 
Service flows are a key feature of the 802.16 standard. A Service Flow represents a 
unidirectional data flow having separate QoS settings for uplink and downlink. Service 
flows provide the ability to set up multiple connections to each subscriber in a sector. 
Separate service flows can be established for uplink and downlink traffic, where each 
service flow is assigned a unique service level category and separate QoS settings. This 
feature allows segregation of high-speed/high-priority traffic from less time-critical 
flows. 
2.3.1 Service 
Flow 
Classification 
Data packets are forwarded by the subscriber based on classification rules. Classification 
rules require examining each packet for pattern matches such as destination address, 
source address, or VLAN tag. All classification is defined at the base station and the 
classification parameters are downloaded to the subscriber. 
RedMAX supports service flows with different classification types including: 802.3 
Ethernet, 802.1Q VLAN, IPV4, IPV4 Over 802.3 and IPV4 Over 802.1Q -- with options 
to classify based on Source and Dest of MAC and IP addresses, VLAN tag and Vlan 
priority, Src and Dst port number, TOS Value and Ethernet protocol type. 
2.3.2  Dynamic Service Addition 
Service flows are defined and stored in the base station. For each service flow to be 
established, the base station sends a setup message to the subscriber specifying the 
required set of QoS parameters. The subscriber responds to each request by accepting or 
rejecting the setup message.  
A service flow may be pre-provisioned or can be dynamically created and deleted 
without service outage. This is useful for supporting multiple subscribers in a single 
sector. New subscribers can be added and existing subscribers can be removed or have 
service levels modified. 
Setup messages are sent by the base station following any subscriber power-cycle, loss 
and recovery of the wireless link to a subscriber, or any service flow add/delete operation 
at the base station.  
2.3.3  Uplink Service Flow Scheduling 
The base station enforces QoS settings for each service flow by controlling all uplink and 
downlink traffic scheduling. This provides non-contention based traffic model with 
predictable transmission characteristics. By analyzing the aggregate requests of all 
subscribers, the base station ensures that uplink and downlink traffic conforms with the 
current service level agreements (SLAs). Centralized scheduling increases traffic 
predictability, eliminates contention, and provides maximum opportunity for reducing 
overhead.