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+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */ |
+/* |
+ * Copyright (c) 2009 IITP RAS |
+ * |
+ * This program is free software; you can redistribute it and/or modify |
+ * it under the terms of the GNU General Public License version 2 as |
+ * published by the Free Software Foundation; |
+ * |
+ * This program is distributed in the hope that it will be useful, |
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of |
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
+ * GNU General Public License for more details. |
+ * |
+ * You should have received a copy of the GNU General Public License |
+ * along with this program; if not, write to the Free Software |
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
+ * |
+ * Authors: Kirill Andreev <andreev@itp.ru> |
+ * Aleksander Safonov <safa@iitp.ru> |
+ * Pavel Boyko <boyko@iitp.ru> |
+ * |
+ * This is top level mesh module description |
+ */ |
+ |
+/** |
+ * \ingroup devices |
+ * \defgroup mesh Mesh |
+ * |
+ * \brief MAC-layer mobile mesh networking. |
+ * \section MeshOverview Overview of Layer-2 Mesh networking protocols |
+ * |
+ * The main goal of this module is to provide MAC-layer routing functionality. |
+ |
+ * The main part of MAC-layer routing model is specific type of a network device -- |
+ * ns3::MeshPointDevice. Being an interface to upper-layer protocols, it provides routing functionality |
+ * hidden from upper-layer protocols, by means of ns3::MeshL2RoutingProtocol. |
+ * |
+ * Our model supports stations with multiple network devices handled by a single |
+ * MAC-layer routing protocol. So, ns3::MeshPointDevice serves as an umbrella to multiple |
+ * network devices ("interfaces") working under the same MAC-layer routing protocol. |
+ * |
+ * Network devices may be of different types, each with a specific medium access method. |
+ * So ns3::MeshL2RoutingProtocol consists of two parts: the one independent from the network device type, |
+ * which we refer to as a routing protocol, and the other one depended on the network device type which |
+ * we refer to as a plug-in to the routing protocol. |
+ * |
+ * One can imagine a MAC-layer routing as a two-tier model. ns3::MeshL2RoutingProtocol and ns3::MeshPointDevice |
+ * belong to the upper tier. The task of ns3::MeshPointDevice is to send, receive, and forward frames, |
+ * while the task of ns3::MeshL2RoutingProtocol is to resolve routes and keep frames waiting for route resolution. |
+ * This functionality is independent from the types of underlying network devices ("interfaces"). |
+ * |
+ * The lower tier implements the part of MAC-layer routing, specific for underlying network devices |
+ * and their medium access control methods. For example, HWMP routing protocol in IEEE802.11s |
+ * uses its own specific management frames. |
+ * |
+ * At present, two routing protocols are implemented in this module: |
+ * - HWMP (default routing protocol for IEEE802.11s standard) + Peer management protocol |
+ * (also described in 802.11s standard draft) which is required by HWMP to manage peer links |
+ * (it works like association mechanism in IEEE802.11). |
+ * - FLAME (Forwarding LAyer for MEshing). |
+ |
+ * While HWMP only works with 802.11-MAC, FLAME works with all types of network devices, which support |
+ * 48-bit MAC-addressing scheme. |
+ * |
+ * \subsection Architecture Architecture of MAC-layer routing stack |
+ * As already mentioned, MAC-layer routing consists of two tiers. |
+ * An ns3::MeshPointDevice which forwards frames by using an attached ns3::MeshL2RoutingProtocol forms |
+ * the upper tier. The interface between ns3::MeshPointDevice and the upper-layer protocols is inherited |
+ * from ns3::NetDevice class. The ns3::MeshPointDevice interacts with ns3::MeshL2RoutingProtocol as follows: |
+ * ns3::MeshPointDevice gives to ns3::MeshL2RoutingProtocol a frame with the source and destination addresses, |
+ * the network device index which the frame is received from, and a callback to be executed when the route is found. |
+ * The callback is needed because all routing queues are implemented inside ns3::MeshL2RoutingProtocol. |
+ * When the route is resolved, ns3::MeshL2RoutingProtocol returns the frame back to ns3::MeshPointDevice with the |
+ * network device index which the packet shall be sent to. All additional routing information is stored inside |
+ * the frame by means of tags. In the end, when all these routines are done, the frame goes to the lower tier. |
+ |
+ * The lower tier is responsible for filling MAC-specific headers. At present, we have only implemented the |
+ * lower tier which is specific for ns3::WifiNetDevice. This tier is implemented as two base classes: |
+ * ns3::MeshWifiInterfaceMac and ns3::MeshWifiInterfaceMacPlugin. The former is a new kind of WifiMac. If beacon |
+ * generation is enabled or disabled, it implements IEEE802.11s mesh functionality or a simple ad hoc functionality |
+ * of the MAC-high part of the WiFi model, respectively. The latter is a plug-in to L2Routing protocol. |
+ * It handles all outgoing and incoming frames, fills headers and make decisions to drop a frame or not. Also, it |
+ * adds information elements to beacons specific to given L2Routing protocol, if needed. |
+ * \image html MeshArchitecture.png "Overview of the Mesh MAC-layer routing system" |
+ * |
+ * \subsection NewProtocol Adding a new protocol |
+ * This module requires all the network devices operate with ns3::Mac48Address addressing scheme. |
+ * |
+ * To add a new L2Routing protocol, one needs to define the following: |
+ * - Write an upper part of the protocol inherited from ns3::MeshL2Routing. |
+ * - If the protocol works only with 802.11 MAC -- write a plug-in inherited from ns3::MeshWifiInterfaceMacPlugin |
+ * - If the protocol works with other types of network devices -- write your own plug-in (interface for |
+ * communication with other types of network devices is not implemented). |
+ * |
+ * When you implement a L2Routing protocol, remember that when you are at L2Routing tier, |
+ * you work with a frame without an LLC header, and when you are at plug-in tier using |
+ * ns3::MeshWifiInterfaceMacPlugin, an LLC header is already attached (by WifiNetDevice) |
+ * |
+ * \attention Note, when you use ns3::MeshWifiInterfaceMac, multiple plug-ins may be installed. |
+ * |
+ * \subsection Statistics |
+ * Each L2Routing protocol has a structure to capture statistics, Report and ResetStats methods. |
+ * This gives an opportunity to collect statistic to an *.xml file periodically. |
+ */ |