802.11g =================== .. toctree:: :maxdepth: 1 :hidden: :includehidden: 802_11g/802_11g 802_11g/mac_functions 802_11g/mac_timings 802_11g/packet_formats 802_11g/power_save 802_11g/interoperability 802_11g/physical_rates 802_11g/ppdu 802_11g/channels 802_11g/PHYs IEEE 802.11g is a Wi-Fi standard that operates in the 2.4 GHz band and supports data rates up to 54 Mbps using OFDM, while maintaining backward compatibility with 802.11b. .. list-table:: :widths: 20 60 20 :header-rows: 1 * - Category - Description - Use Case * - MAC Functions - Handles frame addressing, delimiting, sequencing, and error control at the MAC layer. - Enabling reliable wireless communication in 2.4 GHz networks * - MAC Timings - Uses standard interframe spacing (SIFS, DIFS) and backoff mechanisms for medium access. - Coordinating access in congested 2.4 GHz environments * - Packet Formats - Defines MAC and PHY frame structures including management, control, and data frames. - Packet handling, QoS support, and compatibility with 802.11b * - Power Save - Includes power-saving modes like legacy PSM for efficient energy usage. - Improving battery life in mobile Wi-Fi devices * - Interoperability - Backward-compatible with 802.11b; uses protection mechanisms like RTS/CTS. - Supporting mixed networks with legacy 802.11b devices * - Physical Rates - Offers rates from 1 to 54 Mbps using DSSS and OFDM; dynamically adjusts based on link quality. - Balancing performance and reliability in real-world Wi-Fi use * - PPDU - Defines legacy and extended PPDU formats with preamble and signal fields for modulation and coding info. - Ensuring correct signal decoding and rate negotiation across devices * - Channels - Frequency bands and channel assignments in 802.11g (2.4 GHz) including partially overlapping channels. - Challenges and strategies for efficient spectrum planning and interference mitigation in the crowded 2.4 GHz band. * - PHY Overview - Overview of the Physical Layer in 802.11g, including OFDM and backward compatibility with 802.11b DSSS. - High-speed wireless data delivery (up to 54 Mbps) using robust modulation techniques. .. tab-set:: .. tab-item:: 802.11g **Standard:** IEEE 802.11g (2003) **Main Features:** - Operates in the 2.4 GHz band - Supports data rates up to 54 Mbps - Uses OFDM modulation similar to 802.11a - Backward compatible with 802.11b devices - Combines high speed with wide compatibility **Use Cases:** - Home and small office wireless networks - Environments requiring compatibility with legacy 802.11b devices - General-purpose WLANs with moderate throughput needs - Consumer wireless devices and access points **Related Concepts:** - OFDM modulation and DSSS coexistence - 2.4 GHz interference and channel planning - Backward compatibility mechanisms - Migration path from 802.11b to higher speeds .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Understand the evolution and features of 802.11g:** * :ref:`Learnings in this section <802_11g_step1>` * :ref:`Terminology <802_11g_step2>` * :ref:`Version Info <802_11g_step3>` * :ref:`802_11g Version&IEEE Details <802_11g_step4>` * :ref:`802_11g Basic Setup on Ubuntu using IPv4 <802_11g_step5>` * :ref:`802_11g Basic Setup on Ubuntu using IPv6 <802_11g_step6>` * :ref:`Reference links <802_11g_step16>` .. button-link:: ./802_11g/802_11g.html :color: primary :shadow: :expand: Jump to "802.11g Basics" .. tab-set:: .. tab-item:: 802.11g MAC Functions **Standard:** IEEE 802.11g (2003) **Main Features:** - Inherits MAC layer functionalities from 802.11a and 802.11b - Supports frame delimiting, addressing, error checking, and reliable delivery - Utilizes CSMA/CA for medium access control - Implements optional RTS/CTS protection for coexistence with 802.11b - Manages frame acknowledgments and retransmissions - Enhances throughput via optional frame bursting and block acknowledgment **Use Cases:** - Reliable wireless communication in 2.4 GHz environments - Coexistence with legacy 802.11b devices using protection mechanisms - Supporting multimedia and data applications over legacy hardware **Related Functions:** - Frame aggregation and bursting (optional enhancements) - Protection mechanisms for mixed-mode operation - Fragmentation and reassembly of large packets - Backoff and contention window adjustments .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g MAC Functions:** * :ref:`Reference links ` .. button-link:: ./802_11g/mac_functions.html :color: primary :shadow: :expand: Jump to "802.11g MAC Functions" .. tab-set:: .. tab-item:: 802.11g MAC Timings **Standard:** IEEE 802.11g (2003) **Main Features:** - Defines timing parameters for frame transmission and acknowledgments - Includes Interframe Spaces (SIFS, DIFS, PIFS) to coordinate access - Specifies slot times and contention window for CSMA/CA backoff - Ensures collision avoidance and fair medium access - Manages timing for retransmissions and acknowledgments - Synchronizes MAC and PHY layers for efficient wireless communication **Use Cases:** - Coordinating transmission timing in 2.4 GHz WLANs - Reducing collisions and optimizing throughput - Supporting Quality of Service (QoS) through prioritized timing **Related Timing Parameters:** - Short Interframe Space (SIFS) - Distributed Interframe Space (DIFS) - Arbitration Interframe Space (AIFS) - Slot time and backoff timers .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g MAC Timings:** * :ref:`Reference links ` .. button-link:: ./802_11g/mac_timings.html :color: primary :shadow: :expand: Jump to "802.11g MAC Timings" .. tab-set:: .. tab-item:: 802.11g Packet Formats **Standard:** IEEE 802.11g (2003) **Main Features:** - Defines the structure of MAC and PHY layer frames used in 802.11g - Includes Frame Control, Duration, Address fields, Sequence Control, and CRC - Supports data frames, management frames, and control frames - Uses OFDM and DSSS modulation for compatibility - Frame formats support addressing, QoS, and security features - Allows fragmentation and reassembly for large packets **Use Cases:** - Structuring wireless packets for communication in 2.4 GHz WLANs - Ensuring proper delivery, acknowledgment, and retransmission of data - Enabling interoperability between devices by standardized frame formats **Related Frame Types:** - Management frames (e.g., Beacon, Probe Request) - Control frames (e.g., ACK, RTS, CTS) - Data frames (with or without QoS) .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g Packet Formats:** * :ref:`Reference links ` .. button-link:: ./802_11g/packet_formats.html :color: primary :shadow: :expand: Jump to "802.11g Packet Formats" .. tab-set:: .. tab-item:: 802.11g Power Saving Mechanisms **Standard:** IEEE 802.11g (2003) **Main Features:** - Supports Power Save Mode (PSM) to reduce energy consumption on client devices - Clients enter sleep state and wake periodically to receive buffered data - AP buffers frames for sleeping stations and indicates buffered data in beacon frames - Uses Delivery Traffic Indication Message (DTIM) to inform clients about multicast/broadcast data - Enables efficient battery usage for mobile and portable Wi-Fi devices - Works with MAC layer mechanisms to coordinate sleep and wake cycles **Use Cases:** - Extending battery life of Wi-Fi enabled mobile devices on 2.4 GHz networks - Reducing power consumption in IoT and embedded Wi-Fi devices - Balancing performance and power efficiency in wireless LANs **Related Mechanisms:** - Beacon frame scheduling - DTIM and TIM fields for power management - Client wake-up and sleep signaling .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g Power Saving mechanisms:** * :ref:`Reference links ` .. button-link:: ./802_11g/power_save.html :color: primary :shadow: :expand: Jump to "802.11g Power Saving" .. tab-set:: .. tab-item:: 802.11g Interoperability **Standard:** IEEE 802.11g (2003) **Main Features:** - Ensures compatibility between devices from different vendors using 2.4 GHz band - Supports backward compatibility with 802.11b via DSSS modulation support - Defines common frame formats and signaling to facilitate seamless communication - Implements clear channel assessment (CCA) and CSMA/CA for medium access coordination - Uses standardized management and control frames for association and roaming - Facilitates coexistence with other wireless technologies in overlapping frequency bands **Use Cases:** - Enabling multi-vendor Wi-Fi deployments in enterprise and consumer networks - Supporting seamless handoff and roaming in mixed 802.11b/g environments - Allowing mixed 802.11 standard networks to operate without interference **Related Mechanisms:** - Management frame interoperability - Frequency band coordination - Standardized PHY and MAC layer procedures .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g Interoperability mechanisms:** * :ref:`Reference links ` .. button-link:: ./802_11g/interoperability.html :color: primary :shadow: :expand: Jump to "802.11g Interoperability" .. tab-set:: .. tab-item:: 802.11g Physical Rates **Standard:** IEEE 802.11g (2003) **Main Features:** - Supports multiple physical layer data rates from 1 Mbps up to 54 Mbps - Utilizes OFDM and DSSS modulation for backward compatibility - Provides selectable data rates: 1, 2, 5.5, 6, 9, 11, 12, 18, 24, 36, 48, and 54 Mbps - Adapts rates dynamically based on signal quality and channel conditions - Uses 20 MHz wide channels in the 2.4 GHz frequency band - Enables flexible throughput and reliable wireless communication **Use Cases:** - High-speed wireless networking in consumer and enterprise environments - Multimedia streaming and VoIP over Wi-Fi - Mixed legacy and modern Wi-Fi device support **Related Concepts:** - Rate adaptation algorithms - Modulation and coding schemes (MCS) - Channel bonding and spectrum management .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g Physical Rates:** * :ref:`physical_rates in 802.11g ` * :ref:`Reference links ` .. button-link:: ./802_11g/physical_rates.html :color: primary :shadow: :expand: Jump to "802.11g Physical Rates" .. tab-set:: .. tab-item:: 802.11g PPDU **Standard:** IEEE 802.11g (2003) **Main Features:** - Defines the Physical Protocol Data Unit (PPDU) structure for 802.11g - Includes a preamble for synchronization and channel estimation - Contains SIGNAL field specifying the data rate and length - Payload carries the MAC frame encoded with OFDM or DSSS modulation - Supports various data rates with adaptive modulation and coding - Enables reliable wireless data transmission at 2.4 GHz frequency band **Use Cases:** - Ensuring proper encapsulation of data for transmission over 802.11g PHY - Synchronization between transmitter and receiver - Facilitating robust and efficient wireless communication **Related Concepts:** - OFDM and DSSS symbol structure - Service field and tail bits - Channel coding and interleaving .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g PPDU:** * :ref:`Reference links ` .. button-link:: ./802_11g/ppdu.html :color: primary :shadow: :expand: Jump to "802.11g PPDU" .. tab-set:: .. tab-item:: 802.11g Channels **Standard:** IEEE 802.11g (2003) **Main Features:** - Operates in the 2.4 GHz ISM band with 20 MHz channel bandwidth - Provides up to 14 channels globally, but only 3 non-overlapping channels (1, 6, 11) in most regulatory domains - Uses Direct Sequence Spread Spectrum (DSSS) and Orthogonal Frequency Division Multiplexing (OFDM) - Backward compatible with 802.11b devices - Channel overlap requires careful planning to minimize interference and co-channel congestion - Designed to improve throughput in the crowded 2.4 GHz spectrum **Use Cases:** - Channel planning in home, office, and enterprise environments using 2.4 GHz band - Managing interference from other devices like Bluetooth, microwaves, and cordless phones - Supporting legacy devices while providing higher data rates up to 54 Mbps **Related Concepts:** - DSSS and OFDM modulation schemes - Channel overlap and interference mitigation techniques - Regulatory domains and channel availability differences worldwide .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g Channels:** * :ref:`List of channels ` * :ref:`List of channel widths ` * :ref:`List of Bands ` * :ref:`Reference links ` .. button-link:: ./802_11g/channels.html :color: primary :shadow: :expand: Jump to "802.11g Channels" .. tab-set:: .. tab-item:: 802.11g PHY **Standard:** IEEE 802.11g (2003) **Main Features:** - Uses Orthogonal Frequency Division Multiplexing (OFDM) and Direct Sequence Spread Spectrum (DSSS) at the physical layer - Provides data rates from 1 Mbps to 54 Mbps with adaptive modulation - Employs 52 OFDM subcarriers: 48 for data, 4 for pilot signals, and DSSS support for backward compatibility - Implements convolutional coding and interleaving for improved error resilience - Uses a 20 MHz channel bandwidth with a 4 µs OFDM symbol duration - Operates in the 2.4 GHz frequency band, enabling high-speed wireless transmission while supporting legacy 802.11b devices **Use Cases:** - Delivering higher throughput in legacy 2.4 GHz Wi-Fi environments - Supporting mixed networks with both 802.11b and 802.11g clients - Enabling multimedia streaming, VoIP, and general wireless data transfers in home and enterprise settings **Related Concepts:** - OFDM and DSSS modulation techniques - Adaptive modulation and coding schemes - Preamble, SIGNAL field, and synchronization mechanisms ensuring backward compatibility .. panels:: :container: container pb-4 :column: col-lg-12 p-2 :card: What You Will Learn in This Section **Explore the details of 802.11g PHY:** * :ref:`Reference links ` .. button-link:: ./802_11g/PHYs.html :color: primary :shadow: :expand: Jump to "802.11g PHY"