Search results

Ancient Greeks developed sophisticated long-distance communication, using sound such as whistle, notably the hydraulic telegraph (Aeneas Tacticus, 4th Century BC) for coded messages via water levels in linked jars, and fire/smoke signals (Fryktories) for rapid alerts, using towers for visual relays, alongside physical couriers (runners) and carrier pigeons for messages, revolutionizing military strategy and information sharing.

5G Physical Layer (PHY) techniques are core technologies enabling high speeds, low latency, and massive connectivity by using flexible OFDM waveforms, advanced Multi-Antenna (MIMO/Beamforming), new channel coding (LDPC, Polar), and flexible numerologies for diverse spectrums (sub-6GHz to mmWave). Key elements include beamforming for directed energy, massive MIMO for spectral efficiency, flexible OFDM for varied services, and new channel coding for robust error correction, all designed for scalability and forward compatibility across wide frequency ranges.

The insatiable demand for media-rich content and the increasing availability of advanced devices such as smart phones, tablets, etc., has forced the mobile communications ecosystem to consider the next-generation solutions to address these needs. Already in early commercial deployment, 5G is responding to these needs with options such as small cells, HetNets, carrier aggregation, machine-to-machine, Internet of Things (IoT), relays, device-to-device, massive MIMO and operation in the vast spectrum available in the millimeter-wave range, among others.

The future wireless landscape, often associated with 5G, envisions three types of connectivity: enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communication (URLLC), and massive Machine Type Communication (mMTC). The latter two are seen as two generic types that support Internet of Things (IoT) communication, putting forward new types of requirements and research challenges, such as: protocols that operate with short packets, techniques to achieve and assess extremely high reliability, tradeoffs between massiveness and high-reliability, etc.