Simple Module Ieee80211Mac

Package: inet.linklayer.ieee80211.mac
File: src/linklayer/ieee80211/mac/Ieee80211Mac.ned

C++ definition

Implementation of the 802.11b MAC protocol. This module is intended to be used in combination with the Ieee80211Radio module as the physical layer. (The SnrEval80211 and Decider80211 modules should also work if per-packet bitrate setting gets implemented.)

Encapsulation/decapsulation must be done in the upper layers. (It is typically in the 802.11 management module, see in Ieee80211Nic). The base class for 802.11 frame messages is Ieee80211Frame, but this module expects Ieee80211DataOrMgmtFrame (a subclass) from upper layers (the management module). This module will assign the transmitter address (address 2) and the frame sequence number/fragment number fields in the frames; all other fields must already be filled when this module gets the frame for transmission.

The module has an internal queue, but usually it is to be used with an external passive queue module (its name should be given in the queueModule parameter; specifying "" causes the internal queue to be used). The passive queue module is a simple module whose C++ class implements the IPassiveQueue interface.

Limitations

The following features not supported: 1) fragmentation, 2) power management, 3) polling (PCF). Physical layer algorithms such as frequency hopping and direct sequence spread spectrum are not modelled directly.

Fields related to the above unsupported features are omitted from management frame formats as well (for example, FH/DS/CF parameter sets, beacon/probe timestamp which is related to physical layer synchronization, listen interval which is related to power management, capability information which is related to PCF and other non-modelled features).

Ieee80211Mac

Usage diagram:

The following diagram shows usage relationships between types. Unresolved types are missing from the diagram.

Inheritance diagram:

The following diagram shows inheritance relationships for this type. Unresolved types are missing from the diagram.

Used in compound modules:

Name Type Description
Ieee80211Nic compound module

This NIC implements an 802.11 network interface card. It can be configured via the mgmtType parameter to act as an AP or a STA, or for ad-hoc mode.

Ieee80211NicAdhoc compound module

This NIC implements an 802.11 network interface card in ad-hoc mode.

Ieee80211NicAP compound module

This NIC implements an 802.11 network interface card, in an AP, using infrastructure mode.

Ieee80211NicAPSimplified compound module

This NIC implements an infrastructure mode 802.11 network interface card for a wireless Access Point (AP), but using a simplified mgmt module that does not support handovers.

Ieee80211NicSTA compound module

This NIC implements an 802.11 network interface card, in a STA, using infrastructure mode.

Ieee80211NicSTASimplified compound module

This NIC implements an infrastructure mode 802.11 network interface card for a host (STA), but using a simplified mgmt module that does not support handovers.

Parameters:

Name Type Default value Description
address string "auto"

MAC address as hex string (12 hex digits), or "auto". "auto" values will be replaced by a generated MAC address in init stage 0.

queueModule string ""

name of optional external queue module

maxQueueSize int

max queue length in frames; only used if queueModule==""

bitrate double
rtsThresholdBytes int 2346B

longer messages will be sent using RTS/CTS

retryLimit int -1

maximum number of retries per message, -1 means default

cwMinData int -1

contention window for normal data frames, -1 means default

cwMinBroadcast int -1

contention window for broadcast messages, -1 means default

mtu int 1500

Properties:

Name Value Description
display i=block/layer

Gates:

Name Direction Size Description
uppergateIn input
uppergateOut output
lowergateIn input
lowergateOut output

Source code:

//
// Implementation of the 802.11b MAC protocol. This module is intended
// to be used in combination with the Ieee80211Radio module as the physical
// layer. (The SnrEval80211 and Decider80211 modules should also work if
// per-packet bitrate setting gets implemented.)
//
// Encapsulation/decapsulation must be done in the upper layers. (It is
// typically in the 802.11 management module, see in Ieee80211Nic).
// The base class for 802.11 frame messages is Ieee80211Frame, but this
// module expects Ieee80211DataOrMgmtFrame (a subclass) from upper layers
// (the management module). This module will assign the transmitter address
// (address 2) and the frame sequence number/fragment number fields in the
// frames; all other fields must already be filled when this module gets
// the frame for transmission.
//
// The module has an internal queue, but usually it is to be used with an
// external passive queue module (its name should be given in the queueModule
// parameter; specifying "" causes the internal queue to be used). The passive
// queue module is a simple module whose C++ class implements the IPassiveQueue
// interface.
//
// <b>Limitations</b>
//
// The following features not supported: 1) fragmentation, 2) power management,
// 3) polling (PCF). Physical layer algorithms such as frequency hopping and
// direct sequence spread spectrum are not modelled directly.
//
// Fields related to the above unsupported features are omitted from
// management frame formats as well (for example, FH/DS/CF parameter sets,
// beacon/probe timestamp which is related to physical layer synchronization,
// listen interval which is related to power management, capability information
// which is related to PCF and other non-modelled features).
//
simple Ieee80211Mac
{
    parameters:
        string address = default("auto"); // MAC address as hex string (12 hex digits), or
                                          // "auto". "auto" values will be replaced by
                                          // a generated MAC address in init stage 0.
        string queueModule = default("");    // name of optional external queue module
        int maxQueueSize; // max queue length in frames; only used if queueModule==""
        double bitrate @unit("bps");
        int rtsThresholdBytes @unit("B") = default(2346B); // longer messages will be sent using RTS/CTS
        int retryLimit = default(-1); // maximum number of retries per message, -1 means default
        int cwMinData = default(-1); // contention window for normal data frames, -1 means default
        int cwMinBroadcast = default(-1); // contention window for broadcast messages, -1 means default
        int mtu = default(1500);
        @display("i=block/layer");
    gates:
        input uppergateIn @labels(Ieee80211Frame);
        output uppergateOut @labels(Ieee80211Frame);
        input lowergateIn @labels(Ieee80211Frame);
        output lowergateOut @labels(Ieee80211Frame);
}