3.

1 802.16 MAC and 802.16e MAC

3.1.1 Description
The IEEE 802.16 standard, including MAC layer and PHY layer specifications, defines the air interface
and associated functions of the broadband wireless access system supporting multimedia services. It is
designed for high-range and high-bandwidth wireless access, or Wireless Metropolitan Area Network
(Wireless MAN). The bandwidth is up to 70 Mbps and radio range can go up to 50 kilometers (31 miles).
Its major advantages include:
• High bandwidth and large coverage range
• Multiple service with different QoS guarantees
• Built-in security
• Cost-effective and fast-to-deploy first mile access to public networking
• A cost effective alternative that replaces WiFi and 3G/4G
The IEEE 802.16 is also known as WiMAX, which is a certification mark for products that pass conformity
and interoperability tests for IEEE 802.16 standards.
The basic components of an 802.16 network are Base Stations (BS) and Subscriber Stations (SS) (or
Mobile Stations (MS) in 802.16e). The BS connect to the public networks and serve their registered
subscriber stations. The SS typically serve a building (commercial or residential, or WiFi hot spots). Both
BS and SS are assumed to be static in an 802.16 network (mobility support is added in 802.16e
standard). The basic operation mode of an 802.16 network is called Point to Multi-Point (PMP) where SS
is only one-hop away from BS and can only communicate with its BS, not other neighboring SS.
An optional operational mode called Mesh mode, has no clear distinction between SS and BS. Stations
can talk directly to each other and be more than one-hop away from the BS, and the BS is defined as the
station that provides access to the public network, such as the Internet.
Figure 3-1 shows an illustration of an 802.16 network running under the basic PMP mode.
 

FIGURE 3-1. IEEE 802.16 MAC with PMP Mode

IEEE 802.16e added mobility support to IEEE 802.16. It can support mixed fixed and mobile broadcast
wireless access networks. In the 802.16e specification, Subscriber Stations (SS) are also referred to as
Mobile Stations (MS). Under 802.16e, the MS can handover from one BS to another BS.
1. Neighbor BS information advertisement: The serving BS periodically broadcasts information about
neighboring BSs. This information is then used by MS to guide the neighbor BS scanning. In addition,
the BS also indicates to MS the thresholds that will trigger neighbor BS scan or handover actions.
2. Neighbor BS scanning: When the signal quality/QoS of the serving BS is below a certain threshold, the
MS starts the neighbor BS scanning procedure, seeking available BS and determining their suitability
as targets for handover. During neighbor BS scanning, the MS may also associate with neighboring
BSs to reduce delay in handover.
3. Handover: An MS may perform handover under two conditions, a) when the signal quality of the
serving BS is too low, and b) when the QoS capability of the serving BS cannot fulfill requirements.
Both MS and BS can initiate the handover.
4. Sleep mode: When MS is inactive, it can go to sleep mode in order to save power.
5. Paging: paging is used to reach an MS in idle or sleep mode.
6. Idle mode: An MS can go into idle mode where it periodically listens to DL broadcast traffic without
ranging and registration. This can save overhead on handover when the MS traverses an air-link
environment populated by multiple BS.
7. Authentication and Service Authorization (ASA) server: The access control of MS.
8. Backbone functionalities: The BSs can use the backbone to communicate with each other to exchange
some information for services such as network/BS assisted handovers.
Figure 3-2 shows the IEEE 802.16e Access Network supporting mobility.
 

FIGURE 3-2. IEEE 802.16e Access Network with Mobility Support

The IEEE 802.16 MAC is basically a TDMA type of medium access control protocol. The medium is first
divided into MAC frames, then each MAC frame is divided into a downlink subframe and an uplink
subframe. In the downlink subframe, the BS transmits different bursts to different SSs in TDD way. For
the uplink, different SSs transmit in different uplink bursts that are primarily TDMA. The scheduling of
downlink and uplink bursts is controlled by the BS. SS needs to request bandwidth based on its need.
Thus, the uplink access is usually referred to as TDMA + DAMA.
IEEE 802.16 MAC supports 3 duplex modes. They are TDD, FDD Half-Duplex, and FDD Full-Duplex. The
IEEE 802.16 also defines 4 PHY types including SC, SCa, OFDM, and OFDMA.

3.1.2 Features and Assumptions

This section describes the implemented features, omitted features, assumptions and limitations of the
802.16 MAC model.

3.1.2.1 Implemented Features

The MAC802.16 model of QualNet 5.0 has implemented features defined in both IEEE 802.16 and IEEE
802.16e. The detailed list of implemented features is:
• Point to Multi-Point (PMP) mode.
• Time Division Duplex (TDD) mode:
• MAC frame is divided into downlink subframe and uplink subframe.
• DL-MAP and UL-MAP supporting subchannels of OFDMA PHY.
• Network entry and initialization:
• Channel scan and synchronization with DL channel. Channel lost detection and network re-entry.
• DCD and UCD messages for obtaining and maintaining DL/UL parameters.
• Initial (contention) ranging and periodical ranging.
• Negotiation of basic capability and registration.
• CDMA-based ranging.
• Dynamic flow management including service flow addition, deletion and change.
• Bandwidth management:
• Five service types: UGS, ertPS, rtPS, nrtPS and BE.
 • Polling-based bandwidth requests.
• Contention-based bandwidth requests.
• CDMA-based bandwidth requests.
• Scheduling service at the base station:
• Strict priority-based scheduling for different service types where management messages > UGS >
ertPS > rtPS > nrtPS > BE.
• Within each service type, WFQ scheduling is used for fairness.
• MAC frame construction:
• Downlink (DL) subframe construction.
• Uplink (UL) burst construction.
• PDU concatenation, fragmentation, packing, and CRC.
• Adaptive Modulation and Coding (AMC):
• Signal strength monitoring (UL/DL) and reporting (DL).
• Seven burst profiles for both downlink and uplink transmissions using different coding and
modulation combinations.
• Dynamic switch of burst profiles based on CINR.
• Support for broadcast and multicast flows.
• Convergence Sublayer (CS):
• Classify flows to different service types based on their priority.
• Retrieve accurate QoS parameters of UGS flows.
• Support both IPv4 and IPv6.
• IEEE 802.16e Mobility Support:
• Neighbor information exchange among configured BSs.
• Neighbor BS scanning at SS.
• MS initiated and BS initiated hard handoff.
• Flow disconnection and reconnection.
• Idle mode and paging.
• Sleep mode.
• Interface other networks such as ATM, 802.3, 802.11 at network layer.
• Support 802.16 OFDMA PHY.
• Simple admission control.
• ARQ.

3.1.2.2 Omitted Features

The 802.16 MAC features omitted in QualNet 5.0 are:
• Mesh mode.
• Frequency Division Duplex (FDD) mode.
• Transmission power adjustment during ranging.
• PKM security feature.
• Convergence sublayer doesn't support ATM. No packet header compression.
• SC, SCa, and OFDM 802.16 PHYs.
• Only CBR and VBR traffic generators have been modified to provide correct QoS parameters. For other
types of traffic generators, some default QoS parameters are used.
• Association level 1, 2, and soft handoff.
3.1.2.3 Assumptions and Limitations
None.
 

3.1.3 Command Line Configuration

Application Configuration File Parameters
To select the 802.16 MAC protocol, specify the following parameter in the scenario configuration (.config)
file:
[<Qualifier>] MAC-PROTOCOL MAC802.16
The scope of this parameter declaration can be Global, Node, Subnet, or Interface. See  Section
1.2.1.1 for a description of <Qualifier> for each scope.
 
To use 802.16 MAC as the MAC protocol, 802.16 PHY must be selected as the PHY model.
Note:
See Section 2.1 of this model library for details of configuring 802.16 PHY.
Table 3-1 lists the 802.16 MAC configuration parameters.
The 802.16e MAC protocol provides mobility support. To enable 802.16e MAC, specify the following
parameter in the scenario configuration (.config) file:
[<Qualifier>] MAC-802.16-SUPPORT-MOBILITY YES
The scope of this parameter declaration can be Global, Node, Subnet, or Interface. See  Section
1.2.1.1 for a description of <Qualifier> for each scope.
The default value of the parameter MAC-802.16-SUPPORT-MOBILITY is NO.  Table 3-2 lists the 802.16e
MAC configuration parameters.
All parameters can be qualified by a prefix, which can be a node ID, subnet address, or interface address.
Note that parameters with the prefix “MAC-802.16-BS-” and “MAC-802.16e-BS-” are recognized only by
base station nodes. Subscriber station specific parameters have the prefix “MAC-802.16-SS-” or “MAC-
802.16e-SS-”. Parameters without these prefixes are applicable to both base and subscriber stations. In
general, most parameters are configured for base stations. Subscriber stations learn the related
parameters from their currently associated base stations.
The 802.16 MAC parameters are described in  Table 3-1 . See Section 1.2.1.3 for a description of the
format used for the parameter table.
 

TABLE 3-1. 802.16 MAC Parameters

Parameter Value Description
MAC-802.16- List:
STATION-TYPE • BS This parameter indicates the type of the 802.16 station.
Optional • SS The values are as follows:
• BS: Base Station
Scope Default  :
• SS: Subscriber Station (or Mobile Station (MS) in 802.16e)
All SS

MAC-802.16-BS- Time
FRAME-
DURATION Range This parameter defines the duration of the MAC frame.
>0 The BS schedules transmission each MAC frame by MAC frame. A MAC frame is
Optional then divided into downlink (DL link) and uplink (UL link) under TDD. This parameter
Default  : specifies the length of a MAC frame.
Scope
20MS
All
MAC-802.16-BS- Time
TDD-DL-
Range
DURATION This parameter specifies how long the DL part of a MAC frame is.
>0
Optional Basically, it indicates how the MAC frame is divided between downlink
Default  : transmissions and uplink transmissions.
Scope 10MS
All  

MAC-802.16-BS- Time
TTG
Range This parameter specifies the Transmit/receive Transition Gap.
Optional > 0S This gap is between the DL part and UL part of a MAC frame in order to give the BS
enough time to transit from transmission mode to receiving mode.
Scope Default  :
All 100NS

MAC-802.16-BS- Time
RTG
Range This parameter specifies the Receive/transmit Transition Gap.
Optional > 100NS This gap is necessary for BS to switch from receiving mode to transmitting mode.
This gap is inserted between two MAC frames.
Scope Default  :
All 10US

MAC-802.16-BS- Time
SSTG This parameter specifies the transition gap of a subscriber station from transmitting
Range mode to receiving mode or vice versa.
Optional > 100NS Note that this is a parameter for BS. The BS schedules uplink bursts to different SS.
This gap should be inserted between different uplink bursts to guarantee correct
Scope Default  : transition from SS to SS and avoid interferences.
All 4US

MAC-802.16-BS-
DCD- Time This parameter specifies the interval of DCD packets.
BROADCAST- The DCD management packet contains the DL parameters. An SS must receive at
INTERVAL Range least one DCD packet to acquire the DL parameters before it can synchronize with
see note the downlink channel. Thus, this interval decides how fast an SS can synchronize
Optional with the DL channel. The shorter, the faster. On the other hand, DCD messages are
Default  : overhead. Too short DCD intervals may consume a lot of downlink bandwidth.
Scope 5S Note: The range of this parameter is MAC-802.16-BS-FRAME-DURATION to 10S.
All
MAC-802.16-BS- This parameter specifies the interval of UCD packets.
UCD- Time
BROADCAST- The UCD management message contains a description of the uplink channel. An
Range SS must receive at least one UCD message to acquire uplink channel parameters
INTERVAL before it can synchronize with the UL channel. Thus, this interval affects how fast an
see note
SS can synchronize with the UL channel. The shorter, the faster. On the other hand,
Optional
UCD messages are overhead. Too short UCD intervals may consume a lot of
Default  :
downlink bandwidth.
Scope 5S
Note: The range of this parameter is MAC-802.16-BS-FRAME-DURATION to 10S.
All
MAC-802.16-BS- MIN These two parameters specify the minimum and maximum backoff counter used for
RANGING- Integer contention-based ranging (initial ranging).
BACKOFF-MIN When an SS performs the initial ranging, it has a random backoff before selecting a
Range contention ranging slot to transmit the ranging requests. The SS randomly selects a
Optional ≥ 0 backoff value within its current backoff window. The size of the backoff window is
 from 0 to pow(2, backoff-count). The backoff count is bounded by the minimum and
Default maximum value specified by the above two parameters. When a collision happens
Scope
3 (SS didn't get range reply for its ranging request after a timeout interval), the SS
All   doubles its backoff count until it reaches the maximum value. This is also known as
  binary backoff. Thus, the backoff value affects the speed of network entry. When
MAX there are a lot of SS in one cell, a short backoff value may result in a lot of
MAC-802.16-BS- Integer collisions. However, long backoff values may waste bandwidth.
RANGING-
The backoff is in terms of contention ranging slot. For example, if a SS has a
BACKOFF-MAX Range backoff value as n, it will use the next n+1 contention ranging slot to transmit the
see note ranging request. In this implementation, a BS will allocate 3 contention ranging slot
Optional
in each DL-MAP. A SS will retry 16 times for the ranging requests before it gives up
Default the current DL channel.
Scope
15 Note: The range of this parameter is greater than or equal to MAC-802.16-BS-
All RANGING-BACKOFF-MIN.
 
These two parameters specify the minimum and maximum backoff counter used for
contention-based bandwidth requests.
When an SS sends contention based bandwidth requests, it will have a random
backoff before selecting a contention bandwidth requests slot to transmit the
bandwidth requests. The SS randomly selects a backoff value within its current
backoff window. The size of the backoff window is from 0 to pow(2, backoff-count).
MAC-802.16-BS- MIN The backoff count is bounded by the minimum and maximum values specified by
BANDWIDTH- the above two parameters. When a collision happens (SS didn't get data grant for
Integer its bandwidth request after a timeout interval), the SS will double its backoff count
REQUEST- until it reaches the maximum value. This is also known as binary backoff. Thus, the
BACKOFF-MIN Range backoff value affects the speed of contention based bandwidth requests. When
≥ 0 there are a lot of SS in one cell, a short backoff value may result in a lot of
Optional collisions. However, long backoff value may waste bandwidth.
Default
Scope The backoff is in terms of contention bandwidth request slot. For example, if an SS
3 has a backoff value as n, it will use the next n+1 contention bandwidth request slot
All to transmit the bandwidth requests. In this implementation, a BS will allocate 3
 
  contention bandwidth request slots in each DL-MAP. An SS will retry 16 times
MAX before giving up one contention based bandwidth request. Please note, bandwidth
MAC-802.16-BS-
Integer requests are per service flow based. For UGS flows, there is no need for explicit
BANDWIDTH- bandwidth requests. The BS will allocate enough bandwidth periodically based on
REQUEST- Range the QoS parameters of the UGS service flow.
BACKOFF-MAX
see note Similar to UGS, the BS will allocate enough bandwidth periodically to ertPS flow,
Optional however, SS is able to send bandwidth request to adjust the bandwidth requirement
Default when data grant is too much or not enough for its flow requirement. For rtPS service
Scope 15 flow, the BS will also allocate unicast polling specific to the SS for performing
bandwidth request. The interval of unicast polling is based on the smaller one
All   between the maximal latency of the rtPS flow or 1 second. For nrtPS, BS will
allocate periodical unicast polling too. However, the interval is fixed as 2 seconds.
For best effort (BE) flows, no unicast polling will be allocated. Only contention based
bandwidth requests are used for BE flows. Together, the different polling/bandwidth
allocation methods realize the different service types.
Note: The range of this parameter is greater than or equal to MAC-802.16-BS-
BANDWIDTH-REQUEST-BACKOFF-MIN.

MAC-802.16-BS- Real This parameter specifies the upper limit of the load that BS can handle in the
MAX-ALLOWED- uplink/downlink direction.
UPLINK-LOAD- Range  : BS reserves some bandwidth for control messages and handoffs of existing
LEVEL [0, 1] applications. If you specify the value 0.9, the remaining 10% of the total capacity will
be allocated for management message and handoffs exclusively.
Optional Default  :
0.7
Scope
All
 
MAC-802.16-BS-
MAX-ALLOWED-
DOWNLINK-LOAD-
LEVEL

Optional

Scope
All
MAC-802.16-SS- Time This parameter specifies how long SS will wait for the DCD message before it
WAIT-DCD- decides that it has lost the synchronization of the downlink channel.
TIMEOUT- Range
After timeout, the SS will give up the current DL channel, and move to scan the next
INTERVAL [0, 50] available channel. If one configures the DCD interval, this parameter may also need
to be configured. In a worst case, if this parameter is shorter than the DCD interval,
Optional Default  : the SS may frequently lose DL synchronization and restart.
Scope 25S Note: The default value is 25 seconds, which is 5 times of the default value of DCD
  interval.
All
MAC-802.16-SS- Time This parameter specifies how long a SS will wait for the UCD message before it
WAIT-UCD- decides that it has lost the synchronization of the uplink channel.
TIMEOUT- Range
After timeout, the SS will give up the current UL channel, and move to scan the next
INTERVAL [0, 50] available channel. If one configures the UCD interval, this parameter may also need
to be configured. In a worst case, if this parameter is shorter than the UCD interval,
Optional Default  : the SS may frequently lose UL synchronization and restart.
Scope 25S Note: The default value is 25 seconds, which is 5 times of the default value of UCD
  interval.
All

MAC-802.16- List: This parameter specifies the provisioning class of the SS.
STATION-CLASS • GOLD The data to and from the station will be throttled according to the assigned class.
• SILVER There are three possible values: GOLD, SILVER and BRONZE.
Optional • BRONZE The three values are currently assigned as:

Scope • GOLD 3000000 (bps)

Default  :
• SILVER 1500000 (bps)
All BRONZE • BRONZE 512000 (bps)

Note: The following parameters apply to both BS and SS nodes.

This parameter specifies how long that the BS or SS will wait before it times out a
service flow.
MAC-802.16- Time When an application flow ends, the MAC protocol doesn't get notified due to the
SERVICE-FLOW- lack of the QoS framework. Thus, the BS or SS relies on this timeout to detect
TIMEOUT- Range finished flows. When the queue of a service flow has been idle for longer than this
INTERVAL >0 timeout value, the node will times out the service flow and perform flow deletion.
This parameter is important for releasing resources. If it is shorter than the packet
Optional Default  : interval of an application flow, the node may frequently times out the flow and
perform flow addition again upon the next packet of the flow comes, which may
Scope 15S
result in bandwidth perform. On the other hand, if this time out value is too long,
All   then the node will not be able to detect the end of service flows in time. Thus, the
BS may waste bandwidth to allocate unicast polling to the service flow. This
parameter is not mandatory.

MAC-802.16- List: This parameter indicates the type of contention based bandwidth request.
CONTENTION- • NORMAL NORMAL specifies that the Subscriber Station sends the bandwidth request header,
BASED-BWREQ- • CDMA while CDMA specifies that the Subscriber Station uses the CDMA based
TYPE
Optional
Default  : mechanism. To enable the CDMA based mechanism, set the parameter to CDMA.
Scope NORMAL
All
MAC-802.16- List:
RANGING-TYPE • NORMAL This parameter indicates the initial and periodic ranging type.
Optional • CDMA Ranging is the process of acquiring correct timing offset and power adjustments
such that the SS transmissions are aligned with the BS receive frame and received
Scope Default  : with in the appropriate reception thresholds.

All NORMAL

MAC-802.16-
PACKING- List:
ENABLED • YES
• NO
As per the 802.16 MAC standard, packing/unpacking is a mandatory feature.
Optional
Default  :
Scope
NO
All
MAC-802.16-ARQ- List:
ENABLED This parameter is used to send request for ARQ enabled connection.
• YES
• NO This ARQ mechanism is a part of MAC. This mechanism may be enabled on a per-
Optional connection basis. The per-connection ARQ is specified and negotiated during
Default  : connection creation. A connection cannot have a mixture of ARQ and Non ARQ
Scope traffic and the scope of ARQ is limited to one unidirectional connection.
All NO

Integer
MAC-802.16-ARQ- ARQ window size is the maximum number of unacknowledged ARQ blocks at any
WINDOW-SIZE Range  : given time.

Optional (see An ARQ block is unacknowledged if it has been transmitted but no

note) acknowledgement has been received.
Scope Note: The range of this parameter is 1 to ARQ-BSN-MODULE / 2. In QualNet ARQ-
Default  : BSN-MODULE value is 2^11.
All
256
This parameter specifies the transmitter and receiver delay in frames.

Integer The transmitter delay includes sending (MAC PDUs) and receiving (ARQ feedback)
delays and other implementation dependent delays. If the transmitter is BS, then it
MAC-802.16-ARQ- Range  : also includes other delays such as scheduling and propagation delay.
RETRY-TIMEOUT > 0 The receiver delay includes receiving (MAC PDUs) and sending (ARQ feedback)
delays and other implementation dependent delays. If the receiver is BS, the
Optional Default  : receiver delay also includes other delays like scheduling and propagation delay.

Scope see note If this parameter is 0, MAC-802.16-ARQ-RETRY-TIMEOUT value is considered

infinite. The (MAC-802.16-ARQ-RETRY-TIMEOUT * frame duration) value must lie
All Unit between 0 and (655350 * 2) micro seconds.
micro secs Note: The Default value of this parameter is
DOT16_ARQ_DEFAULT_RETRY_TIMEOUT / 2.
In QualNetDOT16_ARQ_DEFAULT_RETRY_TIMEOUT value is 4.

MAC-802.16-ARQ- Integer This parameter specifies the maximum number of times an ARQ block is resent by
RETRY-COUNT the sender before it is discarded by it.
Range  : Using this variable the value of ARQ-BLOCK-LIFE-TIME can be calculated. (MAC-
Optional [0, 802.16-ARQ-RETRY-COUNT * MAC-802.16-ARQ-RETRY-TIMEOUT). If this
655350] parameter is 0, ARQ-BLOCK-LIFE-TIME value is considered infinite.
 Default  :
Scope 2

All Unit
micro secs
Integer

MAC-802.16-ARQ- Range  :
SYNC-LOSS- [0, This parameter specifies the maximum time interval in frames that
INTERNAL 655350] ARQ_RX_WINDOW_START or ARQ_TX_WINDOW_START shall be allowed to
remain at the same value before declaring a loss of synchronization of the sender
Optional Default  : and receiver state machines when data transfer is known to be active.
Scope 32 If this parameter is 0, then ARQ sync loss value is considered infinite.
All Unit
micro secs
Time
MAC-802.16-ARQ-
RX-PURGE- Range
TIMEOUT This parameter specifies the time interval in frames that the receiver must wait after
[0,
successful reception of a block that does not result in advancement of
655350]
Optional ARQ_RX_WINDOW_START.
Default  : If this parameter is 0 then it waits for an infinite time.
Scope
28
All
 
Integer

Range  :
MAC-802.16-ARQ- [1,
BLOCK-SIZE 2040]
This parameter specifies the length used for portioning an SDUARQ BLOCK SIZE is
Optional Default  : the length used for portioning an SDU into a sequence of ARQ blocks prior to
64 transmission.
Scope
All Unit
bytes
 
 
Table 3-2 lists the 802.16e MAC configuration parameters.

TABLE 3-2. 802.16e MAC Parameters

Parameter Value Description
MAC-802.16e-BS- Integer
PAGING-GROUP-ID
Range
Optional This parameter is used to divide the network in different paging groups. A BS may
≥ 0
be part of one or more paging groups.
Scope Default
All 1
MAC-802.16e-BS-IS- List: This parameter is used for specifying whether the paging controller is co-located
PAGING- • YES with BS.
CONTROLLER
• NO
There can only be one paging controller per network and more than one network
Optional
per simulation.
Default  :
Scope  
NO
All
MAC-802.16e-BS-
PAGING-
CONTROLLER IP
Address This parameter specifies the IP address of the paging controller which is
Optional responsible for carrying out paging related tasks for this BS.
 
Scope
All
MAC-802.16e-BS-
Integer
PAGING-INTERVAL-
LENGTH Range  : This parameter specifies the length of the BS Paging interval.
[1, 5] During this time, BS can send Paging Advertisement messages. The value is
Optional
specified as number of frames.
Scope Default  :
5
All
MAC-802.16e-BS- Integer
PAGING-CYCLE
Range  : This parameter specifies the length of the BS Paging cycle.
Optional ≥ 1 This is the cycle in which the paging message is transmitted within the paging
group. The value is specified as number of frames.
Scope Default  :
All 200
Integer
MAC-802.16e-BS-
PAGING-OFFSET This parameter determines the frame within the cycle in which the paging message
Range  : is transmitted.
Optional see
The value must be smaller than the PAGING CYCLE value and is specified as the
note
number of frames.
Scope
Default  : Note: The Range of this parameter is 1 to MAC-802.16e-BS-PAGING-CYCLE.
All
5
MAC-802.16e- Integer
PAGING-HASHSKIP-
THRESHOLD Range  :
[0, This parameter is used for configuring the number of successive MOB_PAG-ADV
Optional 255] messages that may be sent from a BS without individual notification for an MS.

Scope Default  :
All 0

MAC-802.16-BS-
NEIGHBOR This parameter specifies the neighboring BS of this BS.
List Note: The neighbor BS list could be in the form of {nodeId1,nodeId2...} or {nodeId1
Optional thru nodeId2} or a combination. This parameter is used for 802.16e feature
see note
where neighbor BS defined by this parameter will exchange information
Scope among themselves.
All
MAC-802.16e- Real These three parameters are for SS to perform neighbor BS scanning or handover.
NEIGHBOR-SCAN-
RSS-TRIGGER Default  :
Optional -76
Currently, only the Receive Signal Strength metric is used. BS also uses these
Scope Unit
parameters to decide whether to start a BS-initiated handover process.
All dBm
MAC-802.16e-NEIGHBOR-SCAN-RSS-TRIGGER specifies the threshold to trigger
    the neighbor BS scanning. When the MS detects that the RSS of the current
  serving BS is lower than this threshold, it tries to perform neighbor BS scanning.
MAC-802.16e-
HANDOVER-RSS- MAC-802.16e-HANDOVER-RSS-TRIGGER specifies the threshold to trigger the
Default  : handover. When the MS detects that the RSS of the serving BS is lower than this
TRIGGER
-78 threshold, it will try to select a neighbor BS and perform handover.
Optional MAC-802.16e-HANDOVER-RSS-MARGIN is used for selecting the target BS to
Unit perform handover. When selecting the neighbor BS to perform handover, MS
Scope dBm consider only neighbor BS who’s RSS is bigger than the RSS of the current serving
BS, and that has at least this margin value. This eliminates frequent handovers.
All  
To make the handover work properly, you might need to adjust the values of MAC-
    802.16e-NEIGHBOR-SCAN-RSS-TRIGGER and MAC-802.16e-HANDOVER-RSS-
MAC-802.16e-   TRIGGER. If the values of the two triggers are too large, then the MS may spend a
HANDOVER-RSS- lot of time on neighbor BS scanning or handover. If they are too small, then the MS
MARGIN Default  : may move out of range of serving BS before migrate/handover to a new BS,
1 resulting in the MS lost connection.
Optional
Unit
Scope
dB
All
 

MAC-802.16e-SS-
SUPPORT-IDLE- List:
MODE • YES
• NO This parameter specifies whether or not SS supports idle mode.
Optional Paging would only be enabled if value of this parameter is configured as YES.
Default  :
Scope
NO
All
MAC-802.16e-SS-
SUPPORT-SLEEP- List:
MODE • YES
• NO This parameter specifies whether or not SS supports sleep mode.
Optional  
Default  :
Scope
NO
All
A distinctive feature of 802.16 is its QoS support. It has five service classes to support real-time and non-
real-time communications, as described below.
• Unsolicited Grant Service (UGS): UGS supports real-time service flows that generate a fixed-size data
packet on a periodic basis, e.g., VoIP without silence suppression.
• Extended Real-time Polling Service (ertPS): ertPS supports features of UGS with variable-size data
packets, such as VoIP with silence suppression.
• Real-Time Polling Service (rtPS): rtPS supports real-time service flows that generate variable-size data
packets on a periodic basis, such as MPEG video or VoIP with silence suppression.
• Non-real-time Polling Service (nrtPS): nrtPS supports delay-tolerant data streams consisting of variable-
sized data packets for which a minimum data rate is required, such as FTP or HTTP (web browsing).
• Best Effort (BE): BE service supports data streams for which no minimum service level is required and
therefore may be handled on a space-available basis.
Using the IP protocols precedence field, applications can direct traffic to a specific service class.  Table 3-
3 specifies the mapping between precedence values and service classes.

TABLE 3-3. MAC Layer Service Flow Mapping

MAC Layer Services Precedence
Unsolicited Grant Service 7, 5
Extended Real-time Polling Service 4
Real-time Polling Service 3
Non-real-time Polling Service 6,2,1
Best Effort 0
 

Precedence 6, 2, 1 are all mapped to nrtPS service type. This allows different priorities for nrtPS
flows. However, in the current implementation, the scheduling doesn't support multiple priorities
Note:
inside one service type. WFQ is used for scheduling and its weight is based on the bandwidth need
of the flow.

CBR Application Example

CBR 2 5 0 512 1S 20S 0S PRECEDENCE 0 # assign traffic as BE flow
CBR 2 5 0 512 1S 20S 0S PRECEDENCE 1 # assign traffic as nrtPS flow
CBR 2 5 0 512 1S 20S 0S PRECEDENCE 3 # assign traffic as rtPS flow
CBR 2 5 0 512 1S 20S 0S PRECEDENCE 4 # assign traffic as ertPS flow
CBR 2 5 0 512 1S 20S 0S PRECEDENCE 7 # assign traffic as UGS flow
 
In QualNet , routing traffic uses precedence 6, which is classified as nrtPS flow. Also, the network
layer may affect the QoS if it has fewer queues than eight, as it queues packets of different service
types into one queue. The value of IP-QUEUE-NUM-PRIORITIES should be larger or equal to
Note: eight, otherwise, the application sets a high precedence for its packets and they may be blocked by
lower precedence packets in network queues. Therefore, to fully guarantee the service types,
configure eight queues at the network layer, as follows:
IP-QUEUE-NUM-PRIORITIES 8

3.1.4 GUI Configuration

This section describes how to configure 802.16 MAC and 802.16e MAC in the GUI.
 

General Configuration
To configure the 802.16 MAC and 802.16e MAC parameters, perform the following steps:
1. Go to one of the following locations:
• To set properties at the subnet level, go to Wireless Subnet Properties Editor  > MAC Layer.
• To set properties for a specific interface of a node, go to one of the following locations:
- Interface Properties Editor > Interfaces > Interface # > MAC Layer
- Default Device Properties Editor > Interfaces > Interface # > MAC Layer.
In this section, we show how to configure the 802.16 and 802.16e MAC parameters in the
Wireless Subnet Properties Editor. Parameters can be set in the Interface Properties editor
and Default Device Properties Editor in a similar way.
 
2. Set MAC Protocol to 802.16 and set the dependent parameters listed in Table 3-4 .
 

FIGURE 3-3. Setting 802.16 General Parameters

TABLE 3-4. Command Line Equivalent of 802.16 General Parameters

GUI Parameter Scope of GUI Parameter Command Line Parameter
Station Type Subnet, Interface MAC-802.16-STATION-TYPE

Setting Parameters

• To configure the node as a subscriber station, set  Station Type to Subscriber Station and configure
the subscriber station parameters as described below.
• To configure the node as a base station, set Station Type to Base Station and configure the base
station parameters as described below.
Subscriber Station Configuration
To configure subscriber station parameters, perform the following steps:
1. Set MAC Protocol [=802.16] > Station Type to Subscriber Station and set the dependent parameters
listed in Table 3-5 .

FIGURE 3-4. Setting Subscriber Station Parameters

TABLE 3-5. Command Line Equivalent of Subscriber Station Parameters

Scope of GUI
GUI Parameter Command Line Parameter
Parameter
MAC-802.16-SS-WAIT-DCD-TIMEOUT-
Wait DCD Timeout Interval Subnet, Interface
INTERVAL
MAC-802.16-SS-WAIT-UCD-TIMEOUT-
Wait UCD Timeout Interval Subnet, Interface
INTERVAL
MAC-802.16-SERVICE-FLOW-TIMEOUT-
Service Flow Timeout Interval Subnet, Interface
INTERVAL
Enable Packing Subnet, Interface MAC-802.16-PACKING-ENABLED
Ranging Type Subnet, Interface MAC-802.16-RANGING-TYPE
Contention-based Bandwidth Request MAC-802.16-CONTENTION-BASED-BWREQ-
Subnet, Interface
Type TYPE
Enable Mobility Mode (802.16e) Subnet, Interface MAC-802.16-SUPPORT-MOBILITY
Enable ARQ Subnet, Interface MAC-802.16-ARQ-ENABLED

Setting Parameters

• To enable packing, set Enable Packing to Yes ; otherwise, set Enable Packing to No .

• To enable mobility mode, set Enable Mobility Mode (802.16e) to Yes ; otherwise, set Enable
Mobility Mode (802.16e) to No.
• To enable ARQ, set Enable ARQ to Yes ; otherwise, set Enable ARQ to No .
2. If Enable Mobility Mode (802.16e) is set to Yes , then set the dependent parameters listed in Table
3-6 .

FIGURE 3-5. Setting the Subscriber Station Mobility Mode Parameters

TABLE 3-6. Command Line Equivalent of Subscriber Station Mobility Mode Parameters

GUI Parameter Scope of GUI Parameter Command Line Parameter
Neighbor BS Scanning RSS Trigger Subnet, Interface MAC-802.16e-NEIGHBOR-SCAN-RSS-TRIGGER
Handover RSS Trigger Subnet, Interface MAC-802.16e-HANDOVER-RSS-TRIGGER
Handover RSS Margin Subnet, Interface MAC-802.16e-HANDOVER-RSS-MARGIN
Enable Sleep Mode Subnet, Interface MAC-802.16e-SS-SUPPORT-SLEEP-MODE
Enable Idle Mode Subnet, Interface MAC-802.16e-SS-SUPPORT-IDLE-MODE

Setting Parameters

• To enable sleep mode, set Enable Sleep Mode to Yes ; otherwise, set Enable Sleep Mode to No .
• To enable idle mode, set Enable Idle Mode to Yes ; otherwise, set Enable Idle Mode to No .
3. If MAC Protocol [=802.16] > Station Type [= Subscriber Station] > Enable ARQ is set to Yes , then
set the dependent parameters listed in Table 3-11 .

FIGURE 3-6. Setting ARQ Parameters

TABLE 3-7. Command Line Equivalent of ARQ Parameters

GUI Parameter Scope of GUI Parameter Command Line Parameter
ARQ Window size Subnet, Interface MAC-802.16-ARQ-WINDOW-SIZE
ARQ Retry Timeout Subnet, Interface MAC-802.16-ARQ-RETRY-TIMEOUT
ARQ Retry Count Subnet, Interface MAC-802.16-ARQ-RETRY-COUNT
ARO Sync Loss Interval Subnet, Interface MAC-802.16-ARQ-SYNC-LOSS-INTERVAL
ARQ Receiving Purge Timeout Interval Subnet, Interface MAC-802.16-ARQ-RX-PURGE-TIMEOUT
ARQ Block Size Subnet, Interface MAC-802.16-ARQ-BLOCK-SIZE

Base Station Configuration

To configure base station parameters, perform the following steps:
1. Set MAC Protocol [=802.16] > Station Type to Base Station and set the dependent parameters listed
in Table 3-8 .
 

FIGURE 3-7. Setting Base Station Parameters

TABLE 3-8. Command Line Equivalent of Base Station Parameters

Scope of GUI
GUI Parameter Command Line Parameter
Parameter
MAC Frame Duration Subnet, Interface MAC-802.16-BS-FRAME-DURATION
TDD Downlink Duration Subnet, Interface MAC-802.16-BS-TDD-DL-DURATION
DCD Broadcast Interval Subnet, Interface MAC-802.16-BS-DCD-BROADCAST-INTERVAL
UCD Broadcast Interval Subnet, Interface MAC-802.16-BS-UCD-BROADCAST-INTERVAL
Ranging Minimal Backoff Value Subnet, Interface MAC-802.16-BS-RANGING-BACKOFF-MIN
Ranging Maximal Backoff Value Subnet, Interface MAC-802.16-BS-RANGING-BACKOFF-MAX
Bandwidth Request Minimal Backoff MAC-802.16-BS-BANDWIDTH-REQUEST-
Subnet, Interface
Value BACKOFF-MIN
Bandwidth Request Maximal Backoff MAC-802.16-BS-BANDWIDTH-REQUEST-
Subnet, Interface
Value BACKOFF-MAX
MAC-802.16-SERVICE-FLOW-TIMEOUT-
Service Flow Timeout Interval Subnet, Interface
INTERVAL
Transmit/Receive Transition Gap(TTG) Subnet, Interface MAC-802.16-BS-TTG
Receive /Transmit Transition
Subnet, Interface MAC-802.16-BS-RTG
Gap(RTG)
SS Transition Gap(SSTG) Subnet, Interface MAC-802.16-BS-SSTG
MAC-802.16-MAX-ALLOWED-UPLINK-LOAD-
Maximum Allowed Uplink Load Level Subnet, Interface
LEVEL
Maximum Allowed Downlink Load MAC-802.16-MAX-ALLOWED-DOWNLINK-LOAD-
Subnet, Interface
Level LEVEL
Enable Packing Subnet, Interface MAC-802.16-PACKING-ENABLED
MAC-802.16-BS-ADMISSION-CONTROL-
Admission Control Scheme Subnet, Interface
SCHEME
Ranging Type Subnet, Interface MAC-802.16-RANGING-TYPE
Contention-based Bandwidth Request Subnet, Interface MAC-802.16-CONTENTION-BASED-BWREQ-
Type TYPE
Enable Mobility Mode(802.16e) Subnet, Interface MAC-802.16-SUPPORT-MOBILITY
Enable ARQ Subnet, Interface MAC-802.16-ARQ-ENABLED

Setting Parameters

• To enable packing, set Enable Packing to Yes ; otherwise, set Enable Packing to No .

• To enable Mobility Mode, set Enable Mobility Mode (802.16e) to Yes ; otherwise, set Enable
Mobility Mode (802.16e) to No.
• To enable ARQ, set Enable ARQ to Yes ; otherwise, set Enable ARQ to No .
 

2. If Enable Mobility Mode (802.16e) is set to Yes , then set the dependent parameters listed in Table
3-9 .
 

FIGURE 3-8. Configuring Base Station Mobility Mode Parameters

TABLE 3-9. Command Line Equivalent of Base Station Mobility Mode Parameters

GUI Parameter Scope of GUI Parameter Command Line Parameter
Neighbor BS Scanning RSS Trigger Subnet, Interface MAC-802.16e-NEIGHBOR-SCAN-RSS-TRIGGER
Handover RSS Trigger Subnet, Interface MAC-802.16e-HANDOVER-RSS-TRIGGER
Handover RSS Margin Subnet, Interface MAC-802.16e-HANDOVER-RSS-MARGIN
Neighbor BS List Subnet, Interface MAC-802.16-BS-NEIGHBOR
Configure Idle Mode Parameters Subnet, Interface N/A

Setting Parameters

• To enable idle mode, set Configure Idle Mode Parameters to Yes ; otherwise, set Configure Idle
Mode Parameters to No .
 

3. If Configure Idle Mode Parameters is set to Yes , then set the dependent parameters listed in Table
3-10 .

FIGURE 3-9. Setting Base Station Idle Mode Parameters

 
 TABLE 3-10. Command Line Equivalent of Base Station Idle Mode Parameters
GUI Parameter Scope of GUI Parameter Command Line Parameter
Paging Group Id Subnet, Interface MAC-802.16e-BS-PAGING-GROUP-ID
Configure as Paging Controller Subnet, Interface MAC-802.16e-BS-IS-PAGING-CONTROLLER
Address of Paging Controller Subnet, Interface MAC-802.16e-BS-PAGING-CONTROLLER
Paging Interval Subnet, Interface MAC-802.16e-BS-PAGING-INTERVAL-LENGTH
Paging Cycle Subnet, Interface MAC-802.16e-BS-PAGING-CYCLE
Paging Offset Subnet, Interface MAC-802.16e-BS-PAGING-OFFSET
Paging Hashskip Threshold Subnet, Interface MAC-802.16e-PAGING-HASHSKIP-THRESHOLD

4. If MAC Protocol [=802.16] > Station Type [= Base Station] > Enable ARQ is set to Yes , then set
the dependent parameters listed in Table 3-11 .

FIGURE 3-10. Setting ARQ Parameters

TABLE 3-11. Command Line Equivalent of ARQ Parameters

GUI Parameter Scope of GUI Parameter Command Line Parameter
ARQ Window size Subnet, Interface MAC-802.16-ARQ-WINDOW-SIZE
ARQ Retry Timeout Subnet, Interface MAC-802.16-ARQ-RETRY-TIMEOUT
ARQ Retry Count Subnet, Interface MAC-802.16-ARQ-RETRY-COUNT
ARO Sync Loss Interval Subnet, Interface MAC-802.16-ARQ-SYNC-LOSS-INTERVAL
ARQ Receiving Purge Timeout Interval Subnet, Interface MAC-802.16-ARQ-RX-PURGE-TIMEOUT
ARQ Block Size Subnet, Interface MAC-802.16-ARQ-BLOCK-SIZE

3.1.5 Statistics
This section describes the file and dynamic statistics of the IEEE 802.16 MAC model.

3.1.5.1 File Statistics

Table 3-12 lists the IEEE 802.16 MAC statistics that are output to the statistics (.stat) file at the end of
simulation.
 

TABLE 3-12. 802.16 MAC Statistics

Statistic Description
General Statistics
Station type Indicates the station type of the node; SS for a subscriber station, and BS
 for a base station.

Statistics Collected for Subscriber Stations

Number of data packets from upper layer Number of data packets from upper layer at a SS.
Number of data packets sent in MAC
Number of data packets sent in MAC frames by a SS.
frames
Number of data packets rcvd in MAC
Number of data packets received from MAC layer by a SS.
frames
Number of DL-MAP messages rcvd Number of DL-MAP messages received by a SS.
Number of UL-MAP messages rcvd Number of UL-MAP messages received by a SS.
Number of DCD messages rcvd Number of DCD messages received by a SS.
Number of UCD messages rcvd Number of UCD messages received by a SS.
Number of network entry performed Number of network entry performed by a SS.
Number of RNG-REQ messages sent Number of range request messages sent by a SS.
Number of RNG-RSP messages rcvd Number of range response messages received by a SS.
Number of SBC-REQ messages sent Number of basic capability request messages sent by a SS.
Number of SBC-RSP messages rcvd Number of basic capability response messages received by a SS.
Number of PKM-REQ messages sent Number of public key management request messages sent by a SS.
Number of public key management response messages received by a
Number of PKM-RSP messages rcvd
SS.
Number of REG-REQ messages sent Number of registration request messages sent by a SS.
Number of REG-RSP messages rcvd Number of registration response messages received by a SS.
Number of REP-REQ messages rcvd Number of report request for signal strength messages received by a SS.
Number of REP-RSP messages sent Number of report response for signal strength messages sent by a SS.
Number of DSA-REQ messages rcvd Number of service flow adding request messages received by SS
Number of DSA-RSP messages sent Number of service flow adding response messages sent by a SS
Number of service flow adding acknowledgement messages received by
Number of DSA-ACK messages rcvd
a SS.
Number of DSA-REQ messages sent Number of service flow adding request messages sent by a SS
Number of dynamic service flow management receipt messages received
Number of DSX-RVD messages rcvd
by a SS.
Number of DSA-RSP messages rcvd Number of service flow adding response messages received by a SS.
Number of service flow adding acknowledgement messages sent by a
Number of DSA-ACK messages sent
SS.
Number of DSC-REQ messages rcvd Number of service flow change request messages received by a SS.
Number of DSC-RSP messages sent Number of service flow change response messages sent by a SS.
Number of service flow change acknowledgement messages received by
Number of DSC-ACK messages rcvd
a SS.
Number of DSC-REQ messages sent Number of service flow change request messages sent by a SS.
Number of DSC-RSP messages rcvd Number of service flow change response messages received by a SS.
Number of DSC-ACK messages sent Number of service flow change acknowledgement messages sent by a
 SS.
Number of DSD-REQ messages rcvd Number of service flow deletion request messages received by a SS.
Number of DSD-RSP messages sent Number of service flow deletion response messages sent by a SS.
Number of DSD-REQ messages sent Number of service flow deletion request messages sent by a SS.
Number of DSD-RSP messages rcvd Number of service flow deletion response messages received by a SS.
Number of data packet from upper layer which need to be classified at
Number of data packets to classify
CS sublayer by a SS.
Number of data packets classified Number of packets that were classified at CS sublayer by a SS.
Number of classifiers Number of classifiers created at the CS sublayer by a SS.
Number of ARQ blocks sent Number of ARQ blocks sent by a SS.
Number of ARQ blocks discarded Number of ARQ blocks discarded by a SS.

802.16e Mobility Related Statistics for a SS (only when 802.16e mobility support is enabled)
Number of neighbor BS scanning performed Number of neighbor BS scanning performed by a SS.
Number of handovers performed Number of handovers performed by a SS.
Number of MOB-NBR-ADV messages rcvd Number of neighbor BS advertisement messages received by a SS.
Number of MOB-SCN-REQ messages sent Number of neighbor scanning request messages sent by a SS.
Number of MOB-SCN-RSP messages rcvd Number of neighbor scanning response messages received by a SS.
Number of MOB-SCN-REP messages sent Number of neighbor scanning report messages sent by a SS.
Number of MOB-MSHO-REQ messages
Number of MS initiated handover request messages sent by a SS.
sent
Number of MOB-BSHO-REQ messages
Number of BS initiated handover request messages received by a SS.
rcvd
Number of MOB-HO-IND messages sent Number of handover indication messages sent by a SS.

Statistics Collected for Base Stations

Number of data packets from upper layer Number of data packets from upper layer at a BS.
Number of data packets dropped due to Number of data packets dropped due to the reason that the destination
unknown SS SS is not registered with the BS.
Number of data packets dropped due to SS Number of data packets dropped due to the reason that the SS has
moved out of cell moved out from the cell of the BS.
Number of data packets dropped due to SS Number of data packets dropped due to the reason that the destination
in handover status SS is in handover status.
Number of data packets sent in MAC
Number of data packets sent in MAC frames by a BS.
frames
Number of data packets rcvd in MAC
Number of data packets received in MAC frames by a BS.
frames
Number of DL-MAP messages sent Number of DL-MAP messages sent by a BS.
Number of UL-MAP messages sent Number of UL-MAP messages sent by a BS.
Number of DCD messages sent Number of DCD messages sent by a BS.
Number of UCD messages sent Number of UCD messages sent by a BS.
Number of RNG-REQ messages rcvd Number of range request messages received by a BS.
Number of RNG-RSP messages sent Number of range response messages sent by a BS.
Number of SBC-REQ messages rcvd Number of basic capability request messages received by a BS.
Number of SBC-RSP messages sent Number of basic capability response messages sent by a SS.
Number of PKM-REQ messages rcvd Number of public key management request messages received by a BS.
Number of PKM-RSP messages sent Number of public key management messages sent by a BS.
Number of REG-REQ messages rcvd Number of registration request messages received by a BS.
Number of REG-RSP messages sent Number of registration response messages sent by a BS.
Number of DSA-REQ messages rcvd Number of service flow adding request messages received by a BS.
Number of dynamic service flow management receipt messages sent by
Number of DSX-RVD messages sent
a BS.
Number of DSA-RSP messages sent Number of service flow adding response messages sent by a BS.
Number of service flow adding acknowledgement messages received by
Number of DSA-ACK messages rcvd
a BS.
Number of DSA-REQ messages sent Number of service f low adding request messages sent by a BS
Number of DSA-RSP messages rcvd Number of service flow adding response messages received by a BS.
Number of service flow adding acknowledgement messages sent by a
Number of DSA-ACK messages sent
BS.
Number of DSC-REQ messages rcvd Number of service flow change request messages received by a BS.
Number of DSC-RSP messages sent Number of service flow change response messages sent by a BS.
Number of service flow change acknowledgement messages received by
Number of DSC-ACK messages rcvd
a BS.
Number of DSC-REQ messages sent Number of service flow change request messages sent by a BS.
Number of DSC-RSP messages rcvd Number of service flow change response messages received by a BS.
Number of service flow change acknowledgement messages sent by a
Number of DSC-ACK messages sent
BS.
Number of service flow change request messages rejected by a BS due
Number of DSC-REQ messages rejected
to admission control.
Number of DSD-REQ messages rcvd Number of service flow deletion request messages received by a BS.
Number of DSD-RSP messages sent Number of service flow deletion response messages sent by a BS.
Number of DSD-REQ messages sent Number of service flow deletion request messages sent by a BS.
Number of DSD-RSP messages rcvd Number of service flow deletion response messages received by a BS.
Number of data packet from upper layer which need to be classified at
Number of data packets to classify
CS sublayer by a BS.
Number of data packets classified Number of packets that were classified at CS sublayer by a BS.
Number of classifiers Number of classifiers created at the CS sublayer by a BS.
Number of ARQ blocks sent Number of ARQ blocks sent by a BS.
Number of MOB-TRF-IND messages sent Number of traffic indication messages sent by a BS.

802.16e Mobility Related Statistics for a BS (only when 802.16e mobility support is enabled)
Number of MOB-NBR-ADV messages sent Number of neighbor BS advertisement messages sent by a BS.
Number of MOB-SCN-REQ messages rcvd Number of neighbor scanning request messages received by a BS.
Number of MOB-SCN-RSP messages sent Number of neighbor scanning response messages sent by a BS.
Number of MOB-SCN-REP messages rcvd Number of neighbor scanning report messages received by a BS.
Number of MOB-MSHO-REQ messages
Number of MS initiated handover request messages received by a BS.
rcvd
Number of MOB-BSHO-RSP messages
Number of BS handover response messages sent by a BS.
sent
Number of MOB-BSHO-REQ messages
Number of BS initiated handover request messages sent by a BS.
sent
Number of MOB-HO-IND messages rcvd Number of handover indication messages received by a BS.
Number of Inter-BS Hello messages sent Number of neighbor BS hello messages sent over backbone by a BS.
Number of neighbor BS hello messages received over backbone by a
Number of Inter-BS Hello messages rcvd
BS.
Number of Inter-BS HO Finish messages Number of HO finished notification received by a BS from MS's current
sent serving BS via the backbone.
Number of Inter-BS HO Finish messages Number of HO finished notification sent by a BS to previous serving BS
rcvd via the backbone.
Number of DREG-CMD messages sent Number of de-registration messages sent by a BS.
Number of DREG-REQ messages rcvd Number of de-registration messages received by a BS.
Number of MOB-PAG-ADV messages sent Number of paging broadcast messages sent.

3.1.5.2 Dynamic Statistics

This section lists the dynamic statistics that are enabled for the IEEE 802.16 MAC model. Refer
to Chapter 6 of  QualNet User’s Guide for details of viewing dynamic statistics in the GUI during the
simulation.
The following dynamic statistics are enabled for a subscriber station:
• Last Measured Downlink CINR (dB)
• Last Measured Downlink RSS (dBm)
• Number of Data Packets Transmitted
• Number of Data Packets Received
• Number of Active Neighbor BSs Discovered
The following dynamic statistics are enabled for a base station:
• Number of Data Packets Transmitted
• Number of Data Packets Received
• Number of Data Packets Dropped due to Handover

3.1.6 Sample Scenario

In this section, we use an example to show how you can configure a scenario with 802.16 MAC.

3.1.6.1 Scenario Description

Assume the scenario contains two subnets. Subnet 1 contains node 1 to node 10 and subnet 2 contains
node 11 to node 20. Both subnets run 802.16 MAC with node 1 as the BS of subnet 1 and node 15 as the
BS of subnet 2. The two base stations, node 1 and node 15, are connected via a wired point-to-point link,
as shown in Figure 3-11 .
 
FIGURE 3-11. Topology of Sample Scenario

3.1.6.2 Command Line Configuration

1. Define the two subnets and a point-to-point link between node 1 and node 15.
 
SUBNET N8-0.0 {1 thru 10}
SUBNET N8-1.0 {11 thru 20}
LINK N2-2.0 {1, 15}
 
2. Create two wireless channels.
 
PROPAGATION-CHANNEL-FREQUENCY[0] 10.0e9
PROPAGATION-CHANNEL-FREQUENCY[1] 10.1e9
 
3. Assign channel 0 to subnet 1 and channel 1 to subnet 2.
 
[N8-0.0] PHY-LISTENABLE-CHANNEL-MASK 11
[N8-0.0] PHY-LISTENING-CHANNEL-MASK 10
 
[N8-1.0] PHY-LISTENABLE-CHANNEL-MASK 11
[N8-1.0] PHY-LISTENING-CHANNEL-MASK 01
 
4. Specify 802.16 MAC as the MAC protocol for both subnets.
 
[N8-0.0] MAC-PROTOCOL MAC802.16
[N8-1.0] MAC-PROTOCOL MAC802.16
 
5. Specify node 1 as BS of subnet 1 and node 15 as the BS of subnet 2.
 
[0.0.0.1] MAC-802.16-STATION-TYPE BS // node 1
[0.0.1.5] MAC-802.16-STATION-TYPE BS // node 15
 
6. Enable mobility for all nodes in the subnet.
 
[N8-0.0] MAC-802.16-MOBILITY-SUPPORT YES
[N8-0.1] MAC-802.16-MOBILITY-SUPPORT YES
 
7. Enable ARQ for all the nodes in the subnet.
 
[N8-0.0.0.0] MAC-802.16-ARQ-ENABLED YES
[N8-0.0.1.0] MAC-802.16-ARQ-ENABLED YES
 
8. Specify 802.16 PHY as the radio type for both subnets.
 
[N8-0.0] PHY-MODEL PHY802.16
[N8-0.0] PHY-RX-MODEL PHY802.16
[N8-1.0] PHY-MODEL PHY802.16
[N8-1.0] PHY-RX-MODEL PHY802.16

3.1.6.3 GUI Configuration

To configure the sample scenario in the GUI, perform the following steps:
1. Create two wireless subnets. Subnet 1 contains nodes 1 to 10 and subnet 2 contains nodes 11 to 20.
Connect nodes 1 and 15 using a point-to-point link.
2. Go to Scenario Properties Editor > Channel Properties, set the Number of Channels as 2 and set the
dependent parameters.

FIGURE 3-12. Setting Channels Parameters

3. Go to Wireless Subnet Properties Editor > Physical Layer for subnet 1. Set both Listenable Channel
Mask and Listening Channel Mask to 10 as shown in Figure 3-12 .

FIGURE 3-13. Setting Listenable and Listening Channel Masks

4. Similarly, set the channel masks for subnet 2 to 01.

5. For both subnets, go to Group Wireless Subnet Properties Editor  > Physical Layer and set Radio
Type to 802.16 Radio , as shown in the Figure 3-14 .

FIGURE 3-14. Setting the Radio Type

For both subnets, go to Group Wireless Subnet Properties Editor  > MAC Layer and configure
as: Set MAC Protocol to802.16 , as shown in Figure 3-15 .

FIGURE 3-15. Setting the MAC Protocol

6. Set Enable Mobility Mode (802.16e) to Yes and set the dependent parameters as shown in Figure 3-
8 .
7. Set Enable ARQ to Yes and set the dependent parameters as shown in Figure 3-10 .
8. For the node 1 and node 15, go to Default Device Properties Editor  > Interfaces > MAC Layer, set
MAC Protocol [= 802.16] >Station Type to Base Station as shown in Figure 3-16 .

FIGURE 3-16. Setting Base Station Parameters

3.1.7 Scenarios Included in QualNet

The QualNet distribution includes several verification scenarios for the IEEE 802.16 MAC model. All
scenarios are located in the directory QUALNET_HOME /scenarios/advanced_wireless/802.16. Table 3-
13 lists the sub-directory where each scenario is located.
 TABLE 3-13. IEEE 802.16 MAC Scenarios Included in QualNet
Scenario Description
Admission-Control Shows an example of Admission control scheme procedure for 802.16 network.
ARQ Show the functionality of ARP for 802.16 network
Shows the functionality of cdma based ranging and bandwidth request process for
Cdma
802.16 network.
dualIP Shows the functionality of IEEE 802.16 when ruining with Dual IP.
Fragmentation Shows an example of Fragmentation functionality for 802.16 network.
Idle-Mode Shows an example of IDLE-MODE functionality for 802.16 network.
IPv6-routing-
Shows an example of functionality of IEEE 802.16 when running IPv6 routing protocols.
protocol
mobility_two_cell Shows the functionality of basic handover of IEEE 802.16e.
multicast Shows the functionality of IEEE 802.16 when running with multicast and unicast applications.
Shows an example of the interoperability between 802.16 and wired 802.3 subnet as well as
multi-cell
wireless 802.11 hot spots.
multicell-high- Shows an example of the basic handover functionality of IEEE 802.16e in multicell environment
mobility and with high mobility.
Shows an example of the multiple rates capability of 802.16 using different coding and modulation
combinations. The rates are properly chosen based on signal strengths. In this sample, the signal
multi-rates strength is mainly
decided by the distance between the BS and SS.
packing Shows an example of the Packing functionality for 802.16 network.
Shows an example of the four service types, namely UGS, ertPs, rtPS, nrtPS and BE.
service-types Five flows are defined with different service types. They will get different quality of service based
on their service types
single-cell Shows an example of the basic functionality of a single cell 802.16 network with IPv4.
single-cell-ipv6 Shows an example of the basic functionality of a single cell 802.16 network with IPv6.
SleepMode Shows an example of the sleep mode functionality for 802.16 wireless network.
Shows an example of two separated 802.16 subnets operating on different channels.
two-cell-backbone
The BSs of the two subnets are connected via a wired point-to-point link.
Shows an example of a WiMAX system working in urban environment, i.e., urban terrain and
UrbanEnv
urban propagation.

3.1.8 References
1. IEEE Std 802.16-2004, “Part 16: Air Interface for Fixed Broadband Wireless Access Systems,” IEEE
Standard for Local and metropolitan area networks, Oct. 2004.
2. IEEE Std 802.16e-2005, "Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access
Systems: Amendment 2: Physical and Medium Ac