On the Transport Capability of LAN Cables in All-Analog MIMO-RoC Fronthaul

Centralized Radio Access Network (C-RAN) architecture is the only viable solution to handle the complex interference scenario generated by massive antennas and small cells deployment as required by next generation (5G) mobile networks. In conventional C-RAN, the fronthaul links used to exchange the signal between Base Band Units (BBUs) and Remote Antenna Units (RAUs) are based on digital baseband (BB) signals over optical fibers due to the huge bandwidth required. In this paper we evaluate the transport capability of copper-based all-analog fronthaul architecture called Radio over Copper (RoC) that leverages on the pre-existing LAN cables that are already deployed in buildings and enterprises. In particular, the main contribution of the paper is to evaluate the number of independent BB signals for multiple antennas system that can be transported over multi-pair Cat-5/6/7 cables under a predefined fronthauling transparency condition in terms of maximum BB signal degradation. The MIMO-RoC proves to be a complementary solution to optical fiber for the last 200m toward the RAUs, mostly to reuse the existing LAN cables and to power-supply the RAUs over the same cable

Radio-over-modes for C-RAN architecture with smart optical resources assignment

In this paper we consider a centralized radio access network (C-RAN) architecture with a fully analog fronthaul link between remote radio heads (RRHs) and baseband units (BBUs) based on the radio over fiber (RoF) paradigm. Mode division multiplexing (MDM) and frequency division multiplexing (FDM) are employed to provide an additional multiplexing signal dimension to meet the huge bandwidth requirements of next generation (5G) wireless mobile systems. The main contribution of the paper is to prove that a smart resource assignment between the radio antennas and the mode/frequency dimensions allows the communication over the RRH-BBU link at rates that are comparable to those achieved by an ideal fronthauling where BBU and RRH are assumed to be co-located, even without any complex and costly optical equalization technique. Validation is on the radio-link capabilities employing multiple antennas to meet the demand for massive MIMO technology

“Wake-up time activation” in older adults: first randomized experimental clinical trial

Balance main rely on vestibular, proprioceptive and visual apparatus integrity. In elderly, postural control fails also due to deficit of sensory functions, atrophy of the musculoskeletal system and neuronal reduction. Deterioration of these functions finally lead to abnormality in performing voluntary muscle movements, subjective feeling of vulnerability, insecurity and depression. Besides, physical inactivity (hypokinesia) is a major risk factor for developing coronary artery disease and stroke, contributing to obesity, high blood pressure, hypercholesterolemia and diabetes. For these reasons, especially in elderly, it is important to include physical activity as part of a regular routine. Aim of this randomized controlled trial was to demonstrate that daily subministration of “Wake-up Time Activation” protocol allow individual recovery of balance and tensile properties of periarticular and intra-articular structures, so preventing morning stiffness and reduction of the Range Of Motion (R.O.M.), mainly in the Vertebral Columna. Therefore, we propose to 50 Healthy individuals (age 45-86) of both sexes a peculiar sequence of movements that allow individual recovery of balance and tensile properties of periarticular and intra-articular structures, so preventing morning stiffness and reduction of the Range Of Motion (R.O.M.), mainly in the Vertebral Columna. To verify the effectiveness of this exercises, we scientifically detected, by mean of validated test and instruments, different parameters at tifferent time, for each individual, for two months. Tests were detected at T0 (before starting daily exercises), T1 (after one month of daily exercises), T2 (at the end of the second month of exercises). At each time, on every person, we performed: Cervical Test, Spinal motility, Pelvic motility (mobility); Standing one leg Test (balance); Get up and Go (reactivity); SF-36 (mood/depression); Paint Rating Scales (joint pain). Statistical analysis of obtained results, discussed in detail in the Postrer, scientifically demonstrate that performing of “Wake-up Time Activation” protocol of adapted fisical activity lead to immediate and persistent back pain reduction, articular R.O.M. increase, recovery of balance and coordination, improved autonomy and mood, also in elderly

Stretching optimization for lower limb posterior chain: comparison between two different executions of the same exercise

Stretching of the posterior kinetic chain muscles, especially the hamstrings, is one of the most practiced exercises in all types of physical activity and postural rehabilitation protocols (1). Objective of our experimental trial was to compare the performance of two different variants of muscle stretching (A and B), highlighting for each one the regions of the posterior kinetic chain (lumbar region, gluteus muscles, hamstrings) most affected by the exercise. 161 selected subjects reported on a specific Body Chart the localization of the stretching sensation; the software Pain-drawing (2) was employed for the analysis of the stretching sensation felt by each subject (75 men and 86 women) aged between 20 and 80 years old, with different lifestyles but subjected to defined exclusion criteria (prosthesis, artificial implants, crippling arthritis, flare–up pain, recent surgical procedures). Stretching A is the generally accepted practice available in the literature. The proposed variant (Stretching B) is the experimental suggested procedure which adapts the execution of the exercise on biomechanical reasoning, in order to focus the stretching sensation on the hamstrings muscles and, at the same time, decreasing the stress in the lumbar region. In stretching B, subjects were positioned with lower limb in neutral position, knee with approximately 18° of feeble bending (variable depth, compact rolls in various size, behind popliteal fossa. Notably, results show that the same area has not been affected; when subjects performed Stretching B exercise avoids both the pre-tension of the hamstrings and the lever created by the arms stretched forward, focusing the stretching sensation on the hamstrings muscles and gastrocnemius and affecting only marginally the lumbar region and never the back region. This appears particularly relevant for the prevention of lower back pain and for situation when the stretching of the posterior kinetic chain is performed as a cool-down following physical activity or for rehabilitation purposes

Hybrid beamforming in RoF fronthauling for millimeter-wave radio

In this paper we consider a centralized radio access network (C-RAN) architecture with a fully analog fronthaul link between remote antenna units (Raus) and baseband units (BBUs) based on the radio over fiber (RoF) paradigm. Beamforming to separate uplink signals received from a pool of users is splitted between Rau and BBU. Optical beamforming is performed at the Rau site with the aim of reducing the number of fronthaul channels and the corresponding analog/digital converters at the BBU, as mandatory for millimeter wave (mmWave) radio communication. Digital baseband processing completes the beamforming at the BBU and compensates for optical beamforming imperfections. In this paper the minimum mean square error (MMSE) beamforming is considered, paired with all-analog fronthauling for the uplink. Spatial sparsity of the mmWave channel is leveraged for fronthaul compression through phase-only approximation of the dominant eigenvectors of the channel. Validation is on the radio-link capabilities employing multiple antennas to meet the demand for massive MIMO technology

Sigma-delta PWM waveforms for optical front-hauling

The optical links is one of the driving enablers of distributed antennas systems for future radio access networks (RAN). However, the increasing demand of the wireless band-width is a strong push toward an efficient usage of the fiber whose bandwidth is large, but not unlimited mainly if considering the electronics. Examples in the direction of bandwidth parsimony are the analog relaying of RAN signals according to the radio-over-fiber paradigm. In this paper we propose the transport of analog RAN signals by employing the pulse width modulation (PWM) as novel waveform for optical front-hauling. At transmitter the radio-signal is sampled and mapped onto the duration of on/off optical signal, at receiving end of the fiber each PW modulated sample is digitized so that the overall communication is transparent. The key contribution here stems from the noise-rejection capability of closed-loop PWM that trades some oversampling and filtering to gain in signal quality. The paper proposes a Sigma-Delta structure for PWM that is purposely designed to trade these benefits for RAN front-hauling architecture. Simulation results provide some room for discussion on pros/cons of this novel front-hauling

Space-frequency to space-frequency for MIMO radio over copper

Centralized Radio Access Network (C-RAN) architecture is considered the only viable solution to handle the complex interference scenarios generated by massive antenna and small cell deployment foreseen for next generation (5G) mobile networks. The fronthaul links used to exchange the signal between Base Band Units (BBUs) and Remote Radio Heads (RRHs) are conventionally based on optical fiber, due to its huge bandwidth. In this paper we propose the radio over copper (RoC) as a complementary technology for the fronthaul architectures leveraging on the pre-existing LAN cables that are largely deployed in buildings and enterprises. To fully exploit the capabilities of LAN cable over the last 50-200m, a joint space and frequency division multiplexing is proposed. In particular, the main contribution of the paper is to prove that a smart mapping between the radio antennas/spectrum and the copper cable space/frequency dimensions allows an efficient communication over the RRH-BBU link with performances that are comparable to those achieved by an ideal fronthauling where BBU and RRH are assumed to be co-located. Validation is on the radio-link capabilities of RoC over Cat-6 cable to meet the demand for massive MIMO technology

Optical multilevel pulsewidth modulation for analog mobile fronthaul

The evolution of radio access networks is towards a centralized architecture (C-RAN), with massive antenna deployments and large radio-frequency bandwidths. In the next future, traditional optical transport technologies based on digital radio over fiber will no longer be able to support the mobile fronthaul traffic connecting antennas hosted at remote radio units and centralized baseband units. Analog radio over fiber can be selected to support the mobile fronthaul (MFH) network and, in particular, pulse width modulation (PWM) is a viable alternative for analog signal transport. In order to increase the MFH spectral efficiency, we propose to exploit multilevel PWM (M-PWM) in a wavelength division multiplexing-passive optical network (WDM-PON) network, comparing its performance with a conventional 2-level PWM solution. Experimental results show successful transmission over 7.5-km standard single mode fiber (SSMF) of up to 16 aggregated LTE-like 20-MHz signals with 64-QAM on each subcarrier, while up to eight aggregated LTE-like 20-MHz signals with 256-QAM could be supported. M-PWM thus allows either using higher order modulation formats or aggregating a higher number of LTE channels