Performance Differentiation 2.13.3 Characteristics of the Fourier Transform 2.13.4 The IDFT and DFT as Used in a WiFi Transceiver 2.13.5 Properties of a Sinusoid 2.13.6 The IDFT and DFT in Wide-Area OFDM (LTE) 2.13.7 The Impact of Transforms on DSP and Microcontroller Architectures - Maths in the Microcontroller 2.13.8 How Fourier Transforms Add Value 2.13.9 Power Drain and Battery Capacity Chapter Summary Interrelationship of the Physical Layer with Other Layers of the OSI Model MAC Layer and Physical Layer Relationships OFDM and the Transformative Power of Transforms 3.2.1 The Origins of Matrix Maths and the Hadamard Transform 3.2.2 The Hadamard Matrix and the Hadamard Transform 3.2.3 The Properties of a Hadamard Matrix 3.2.4 Differences Between the FFT and the FHT 3.2.5 Some Naming Issues 3.2.6 How the FHT and FFT Deliver Cost Reduction 3.2.7 The Need to Deliver Cost Reduction and Better Performance The Role of Binary Arithmetic in Achieving Sensitivity, Selectivity and Stability 3.3.1 Coding Distance and Bandwidth Gain 3.3.2 An Example - The Barker Code Used in Legacy 802.11 b WiFi Systems 3.3.3 Complementary Code Keying used in 802.11 b 3.3.4 Walsh Codes used in IS95 CDMA/1EX EV 3.3.5 OVSF Codes in W-CDMA 3.3.6 CDMA/OFDM Hybrids as a Solution Contents Summary Contention Algorithms 3.5.1 802.11 QOS and Prioritisation 3.5.2 802.11 f Handover 3.5.3 802.11 h Power Control 3.5.4 802.11 i Authentication and Encryption 3.5.5 802.11 j Interworking 3.5.6 802.11 k Measurement Reporting 3.5.7 802.11 n Stream Multiplexing 3.5.8 802.11 S Mesh Networking The WiFi PHY and MAC Relationship 3.6.1 Voice and Video Frame Lengths and Arrival Rates 3.6.2 Data Throughput - Distance and MAC Overheads 3.6.3 Mobility, Handover and Power Control Overheads 3.6.4 Impact of Receive Sensitivity on the Link Budget 3.6.5 Linearity Requirements 3.6.6 WiFi's Spectral-Efficiency and Power-Efficiency Limitations 3.6.7 Why WiFi for IP Voice and Video? LTE Scheduling Gain 3.7.1 LTE QOE and Compression 3.7.2 MOS and QOS 3.7.3 The Cost of Store and