Multi-channel Networks Research Articles

The video bubble

Multichannel networks (MCNs) are intermediary companies that sell advertising, cross-promote affiliated YouTube channels, and develop video brands. They have often been criticized as driving YouTube’s commercialization, a seemingly recent phenomenon that sees hithertho informal practices of video making and sharing being increasingly formalized. This article challenges such beliefs about YouTube’s sudden makeover, based on archival evidence that allows to reconstruct YouTube’s long commercial history and on fresh field study data relating to one specific MCN and its content providers. Debunking the myth of ‘cocreation’, the article uses simple analogies – market, infrastructure, and franchise – to describe how MCNs contribute to establish asymmetrical relations between users and emergent industry systems online. It demonstrates how MCNs since 2006 have streamlined and standardized production inputs, reorganized cost per mille–based ad sales, and redefined the value of video in line with a more general financialization of media markets. The methodological framework for this empirical inquiry into YouTube’s first decade is based on economic sociology and infrastructure studies, and the argument itself framed by critical research on ‘connected viewing’, a larger trend across the media industries to integrate digital technology and socially networked communication with traditional screen media practices.

Content-Based Multi-Channel Network Coding Algorithm in the Millimeter-Wave Sensor Network.

With the development of wireless technology, the widespread use of 5G is already an irreversible trend, and millimeter-wave sensor networks are becoming more and more common. However, due to the high degree of complexity and bandwidth bottlenecks, the millimeter-wave sensor network still faces numerous problems. In this paper, we propose a novel content-based multi-channel network coding algorithm, which uses the functions of data fusion, multi-channel and network coding to improve the data transmission; the algorithm is referred to as content-based multi-channel network coding (CMNC). The CMNC algorithm provides a fusion-driven model based on the Dempster-Shafer (D-S) evidence theory to classify the sensor nodes into different classes according to the data content. By using the result of the classification, the CMNC algorithm also provides the channel assignment strategy and uses network coding to further improve the quality of data transmission in the millimeter-wave sensor network. Extensive simulations are carried out and compared to other methods. Our simulation results show that the proposed CMNC algorithm can effectively improve the quality of data transmission and has better performance than the compared methods.

Distributed Channel Allocation for Ad-hoc Multichannel Cognitive Radio Networks

Cognitive radio network was proposed to use the spectrum resource more efficiently. In a multichannel ad-hoc cognitive radio network, there is no central station and requires distributed channel scheduling. An important requirement of the cognitive radio network is to avoid interference to primary networks. In this paper, the authors propose the distributed packet scheduling scheme for ad-hoc multichannel cognitive radio networks. Each secondary user calculates independently its own priority with probabilistic manner and selects one of multi channels considering the primary user’s traffic pattern to minimize interference to the primary networks.

YouTube, multichannel networks and the accelerated evolution of the new screen ecology

In attempting to break with a ‘fall from grace’ narrative that may structure analysis of the rapid professionalization and monetization of previously amateur online video content on the main global platform, YouTube, this article outlines histories of key institutions in the new screen ecology as outcomes of the increased interpenetration of very different, often clashing industry cultures. Google/YouTube, Apple’s iTunes, Netflix, Amazon, Yahoo! and Facebook (‘NoCal’) are largely Internet ‘pure-play’ companies, whilst Hollywood’s incumbents (‘SoCal’) practice time-honoured mass media and premium content strategies. The ‘history of the present’ of the new screen ecology is the history of the clash of these cultures. The less than 10-year history of Google’s YouTube can be written as a history of Google seeking to come to terms with the conditions of possibility for entertainment, content and talent development from its base as an IT company dedicated to scale, automation, permanent beta, rapid prototyping and iteration. These efforts reflect both continuities and contestations with traditional media models, particularly business models. As emerging intermediaries in the middle of the convergent space between NoCal and SoCal, multichannel networks’ (MCNs’) placement sees them needing to innovate on both the NoCal and SoCal side. On the former side, MCNs are attempting to provide value-added services superior to basic YouTube analytics, with programmatics and pioneering attempts at management of scale and volume. On the latter side, they are managing a quite different class of entry- to mid-level talent, who bring successful audience development and clear ideas about the roots of their success with them. The new screen ecology is a space of unimagined scale and scope of flourishing online creativity and culture, which is at the same time turbulent and precarious for creators and MCNs alike.

Spatial fairness in multi-channel CSMA line networks

In this paper we consider a multi-channel random-access carrier-sense multiple access (CSMA) line network with n saturated links, where each link can be active on at most k of the C available channels at any time. Using the product form solution of such a network, we develop fast algorithms to compute the per-link throughputs and use these to study the spatial fairness in such a network.Recently it was shown that fairness in a single channel CSMA line network can be achieved by means of a simple formula for the activation rates, which depends solely on the number of interfering neighbors. In this paper we show that this formula still achieves fairness in the multi-channel setting under heavy traffic, but no such simple formula seems to exist in general, unless k equals C. On the other hand, numerical experiments show that the fairness index when using the simple single channel formula in the multi-channel setting is close to one and tends to improve as k increases. In other words this simple formula eliminates most of the spatial unfairness in a multi-channel network, especially when k is close to C.

A Distributed Opportunistic MAC Protocol for Multichannel Wireless Networks

We propose a distributed opportunistic medium access control (MAC) scheme for maximizing the expected aggregate throughput in a multichannel wireless network such as a clustered orthogonal frequency-division multiple access (OFDMA) network. In our proposed scheme, each user attempts to send only on its best channel and transmits if the best-channel gain is higher than a given threshold, which is dynamically updated depending on previous idle and collision situations. In this way, with our proposed scheme, in a homogeneous system where the channel fading distribution is identical for all users, the best user for each channel is obtained in a distributed manner. We also obtain the optimal values of the thresholds so that the probability of successful transmission is maximized and a minimal number of transmission opportunities are wasted (e.g., due to collision or idle transmissions). In the asymptotic limit of a large number of users and sufficiently long transmission slot duration, we show that, in comparison with the optimal centralized scheme, the throughput loss for our proposed scheme goes to zero. Furthermore, we extend our distributed opportunistic MAC scheme for a homogeneous system to that for a heterogeneous system where the channel fading distribution is heterogeneous across users. Throughput performances and signaling overhead are analyzed for the proposed distributed MAC schemes and compared with those of the existing schemes. Simulation results show that our proposed schemes significantly improve the average aggregate throughput when compared with the existing schemes.

What's new about new media? How multi-channel networks work with content creators

With the rise and rapid proliferation of digital and online marketing, increased cord-cutting by consumers, and new content being created online, Internet-based advertising is the single fastest-growing ad expenditure category, outstripping TV, radio, and other more traditional media formats. With the rise of new media and the increased content creation, the ability of content creators to manage and guide their brand has become more important than ever. This article investigates one such mechanism for managing the new media phenomenon, the Multi-Channel Network (MCN) model. An MCN is any entity or organization which either partners with content creators or directly produces a variety of distinctive content and works to perform business and marketing functions on the platform in which said content is released. This article investigates the MCN phenomena as it specifically addresses the needs of content creators in the new prosumptive consumer culture that helps inform and create new media content. It highlights strategies for managing and navigating the new media and MCN domain.

On Throughput Maximization in Multichannel Cognitive Radio Networks Via Generalized Access Strategy

Spectrum access strategy plays a critical role in multichannel cognitive radio networks (CRNs). However, the CRNs cannot obtain the maximal throughput, when the existing access strategies, including overlay, underlay, and hybrid access strategies, are applied to multichannel CRNs. In this paper, we present a generalized access strategy in a multichannel CRN smart home environment, in which a secondary user (SU) system selects part of channels for sequential spectrum sensing, and accesses these channels based on the sensing results. Moreover, it accesses the remaining channels directly. We then formulate a two-phase optimization framework, which takes the sensing channel selection, sensing time allocation, and the power allocation into consideration, to maximize the gross average throughput of the multichannel CRN. In the sensing phase, a generalized access strategy algorithm (GAS) is first proposed, where we prove that only part of channels needs to be selected for spectrum sensing to achieve the maximum throughput. An optimal stopping rule is proposed to determine the optimal number of selected sensing channels. In addition, a completed hybrid access strategy algorithm is further investigated where the SU system senses all channels. An approximation algorithm is also presented to achieve suboptimal results with low computational complexity. In the transmission phase, the transmission powers of all channels are optimized via convex algorithms. Numerical experiments show that, compared with the existing schemes, the proposed schemes are able to achieve considerable throughput improvement.

Distributed Joint Rate Control, Resource Allocation, and Congestion Control for Throughput Optimization in Multirate Multiradio Multichannel Wireless Network with Intersession/Intrasession Network Coding

Wireless multihop networks are increasingly used because of their low cost and easy deployment. However, there are still many restrictions that degrade performance. Network coding has been proposed to improve the throughput of a wireless network through the characteristics of overhearing and broadcast. In this paper, we model the network utility maximization problem using a combined intrasession and intersession network coding method to improve the network utility in multiradio, multichannel, and multirate wireless network. And we propose a network throughput optimization scheme with a rate control, resource allocation and congestion control algorithm. We formulate an optimal framework reflecting wireless network environment. Also, we propose a rate selection scheme to choose the transmission rate on each node. We evaluate the proposed algorithms by simulation. The performance evaluation results show that the proposed scheme can improve throughput for network by utility optimization in a multiradio, multichannel, and multirate wireless network.

Exploiting Overlapped Bands for Efficient Broadcast in Multi-channel Wireless Networks

In wireless networks, broadcasting is a fundamental communication primitive for network management and information sharing. However, in multichannel networks, broadcast efficiency is very poor as devices are distributed across various channels. Thus, a sender tries all channels to broadcast a single message, causing large overhead. In this paper, we propose a novel, drastically different scheme for efficient broadcast in multichannel networks. Our scheme leverages an overlapped band of adjacent channels, which is the frequency range that partially overlapped channels share within their channel boundaries. Specifically, a sender advertises a rendezvous channel through the overlapped band of adjacent channels; message sharing is done on the rendezvous channel. Our scheme employs signaling via overlapped band (SOB), which defines a new signal processing mechanism for communication via the overlapped band. SOB is integrated with the following Multiple Access Control (MAC) layer mechanisms: 1) Reserve idle spectrum fragment to reduce waiting time, 2) multisender agreement on rendezvous channel to support multisender broadcasts, and 3) reinforce switch notification to reduce the residing time at a wrong channel. Our scheme can also be integrated with two remarkably simple but efficient mechanisms for improving the packet delivery ratio and reducing delay in a multiple contention domain. We implemented our scheme on the SORA software radio platform. Experimental results validated communication through the overlapped band. Intensive simulation studies showed that our scheme dramatically outperformed a previous approach.

Flow control using audio tones in resonant microfluidic networks: towards cell-phone controlled lab-on-a-chip devices.

Fluid control remains a challenge in development of portable lab-on-a-chip devices. Here, we show that microfluidic networks driven by single-frequency audio tones create resonant oscillating flow that is predicted by equivalent electrical circuit models. We fabricated microfluidic devices with fluidic resistors (R), inductors (L), and capacitors (C) to create RLC networks with band-pass resonance in the audible frequency range available on portable audio devices. Microfluidic devices were fabricated from laser-cut adhesive plastic, and a "buzzer" was glued to a diaphragm (capacitor) to integrate the actuator on the device. The AC flowrate magnitude was measured by imaging oscillation of bead tracers to allow direct comparison to the RLC circuit model across the frequency range. We present a systematic build-up from single-channel systems to multi-channel (3-channel) networks, and show that RLC circuit models predict complex frequency-dependent interactions within multi-channel networks. Finally, we show that adding flow rectifying valves to the network creates pumps that can be driven by amplified and non-amplified audio tones from common audio devices (iPod and iPhone). This work shows that RLC circuit models predict resonant flow responses in multi-channel fluidic networks as a step towards microfluidic devices controlled by audio tones.

"When To Go It Alone: Start-ups, Alliances, and Resource Accumulation"

Should entrepreneurs go at it alone? Using newly- collected data on media entrepreneurs on YouTube, this paper estimates the impact of entrepreneurs’ alliance with Multi-Channel Networks (MCN) on t...

Self-motivated Packet Shifting in Multichannel Network

The range admittance in Adhoc Network by allowing the inferior user nodes to use the channel as extended as the broadcast does not affect the main user. This paper involves a new Point squash based Precedence Development system with Self-motivated Packet Shifting which is planned for dispersed multichannel system to improve the system performance. It also presents the Channel Intelligence and essential Intelligence techniques before the progress of the channels. Based on biased queue-balancing and entropy flow control which might be suited for self motivated changing packets in Adhoc networks, this system proposes a Self motivated Packet Shifting algorithm for most favourable packet shifting between different channels during the packet broadcast. The projected protocol will directly observe the channel to make a decision where the packet is to be shifted within the n-channels for most favourable throughput. Factors of these projected systems are configured to sustain the network permanence. The results show that the proposed system improves the presentation in conditions of throughput and packet delivery ratio by borrowing the certified range and protects main users from interference.

On Capacity and Delay of Multichannel Wireless Networks With Infrastructure Support

In this paper, we propose a novel multi-channel network with infrastructure support, called an MC-IS network, which has not been studied in the literature. To the best of our knowledge, we are the first to study such an MC-IS network. Our proposed MC-IS network has a number of advantages over three existing conventional networks, namely a single-channel wireless ad hoc network (called an SC-AH network), a multi-channel wireless ad hoc network (called an MC-AH network) and a single-channel network with infrastructure support (called an SC-IS network). In particular, the network capacity of our proposed MC-IS network is $\sqrt{n \log n}$ times higher than that of an SC-AH network and an MC-AH network and the same as that of an SC-IS network, where $n$ is the number of nodes in the network. The average delay of our MC-IS network is $\sqrt{\log n/n}$ times lower than that of an SC-AH network and an MC-AH network, and $\min\{C_I,m\}$ times lower than the average delay of an SC-IS network, where $C_I$ and $m$ denote the number of channels dedicated for infrastructure communications and the number of interfaces mounted at each infrastructure node, respectively. Our analysis on an MC-IS network equipped with omni-directional antennas only has been extended to an MC-IS network equipped with directional antennas only, which are named as an MC-IS-DA network. We show that an MC-IS-DA network has an even lower delay of $\frac{c}{\lfloor \frac{2\pi}{\theta}\rfloor \cdot C_I}$ compared with an SC-IS network and our MC-IS network. For example, when $C_I=12$ and $\theta=\frac{\pi}{12}$, an MC-IS-DA network can further reduce the delay by 24 times lower that of an MC-IS network and reduce the delay by 288 times lower than that of an SC-IS network.

The Multi-channel Embedded Video Surveillance Alarm System

The system is used to measure temperatures and monitor by videos in multi-channels. For example, it can be used to care for babies in home while parents go to work. Each room has a baby's body wireless temperature sensor to measure his or her temperature and a webcam. The temperature sensors can transmit the babies’ temperatures to the gateway by the wireless multi-channel network. The linux operating system is installed on the gateway. The data base saves each baby’s temperature. And the developed software can display all the temperatures on one screen in the form of split-screen or on one’s own. In addition, each WIFI wireless camera system is also fixed in the corresponding crib. The camera catches the video and transmits it via the 3g module through the wireless multi-channel network. The H.264 coded video is transmitted to the gateway through the RTP protocol. The collected multi-channel videos are also displayed on the screen of the gateway respectively or simultaneously. In the gateway, the video is captured using FFMPEG solution through the H.264 decoding and the RTP protocol. Each mother can view what the baby is doing and her baby's body temperature by her mobile phone through the WIFI in her company at any time. When the baby is in the abnormal situation, the alarm system is activated automatically. The system can also apply widely in other aspects.

Performance Evaluation of Multi-Channel Wireless Backoff Algorithm

Wireless technologies are the critical components that facilitate ubiquitous communications among users, devices, and humans-machines. IEEE 802.11 is a popular wireless access technology which uses a truncated binary exponential backoff algorithm in a shared channel. But its performance deteriorates rapidly if there are numerous simultaneous active connections. Multi-channel wireless network, consisting of control and data channels, is one possible solution to offer sustainable high performance large-scale networks. In this letter, we analyze the performance of a multi-channel backoff (MCB) algorithm, which gives a non-zero performance bound for large network sizes. Through simulations and analysis, settings of associated system parameters are determined to offer high goodput performance.

Wavelength channel minimization-based energy-aware mechanism in a multichannel EPON

We propose an energy-aware mechanism (EAM) applicable to the multichannel Ethernet Passive Optical Network that can minimize the number of wavelength channels used and save energy. Wavelength channel minimization is processed by collecting the information such as request message, allocated grant, and start time of each optical network unit (ONU) transmission in the previously elapsed scheduling cycles and comparing it with the buffer occupancy and packet delay conditions of the ONUs required by the user's quality-of-service requirement. They are exchanged between the optical line terminal (OLT) and the ONUs via the multipoint control protocol. In this way, at the beginning of each scheduling cycle, the ONU's buffer occupancy and packet delay conditions can be evaluated, and then, the OLT decides the smallest number of wavelength channels to be used in the current scheduling cycle. By turning off the OLT receivers corresponding to the unused wavelength channels, the OLT can save energy. The performance of the proposed EAM was evaluated through simulations using nonjoint off-line dynamic bandwidth allocation and dynamic wavelength assignment algorithms. The results showed that the OLT receivers' power consumption could be reduced by 48 % on average.

Channel-quality-aware multihop broadcast for asynchronous multi-channel wireless sensor networks

In this paper, we propose Multi-channel EMBA (M-EMBA), efficient multihop broadcast for asynchronous multi-channel wireless sensor networks. Our scheme employs two channel-quality-aware forwarding policies of improved forwarder's guidance and fast forwarding to improve multihop broadcast performance. The improved forwarder's guidance allows forwarders to transmit broadcast messages with guidance to their receivers through channels with good quality. The guidance indicates how each receiver should forward the broadcast message to its neighbor nodes. The improved forwarder's guidance tremendously reduces redundant transmissions and collisions. Fast forwarding allows adjacent forwarders to send their broadcast messages simultaneously through different channels that have good quality, which helps to reduce multihop broadcast latency and improve multi-channel broadcast utility. In this work, we evaluate the multihop broadcast performance of M-EMBA through theoretical analysis of the system design and empirical simulation-based analysis. We implement M-EMBA in ns-2 and compare it with the broadcast schemes of ARM, EM-MAC, and MuchMAC. The performance results show that M-EMBA outperforms these protocols in both light and heavy network traffic. M-EMBA reduces message cost in terms of goodput, total bytes transmitted, as well as broadcast redundancy and collision. M-EMBA also achieves a high broadcast success ratio and low multihop broadcast latency. Finally, M-EMBA significantly improves energy efficiency by reducing average duty cycle.

MaxWeight Versus BackPressure: Routing and Scheduling in Multichannel Relay Networks

We study routing and scheduling algorithms for relay-assisted, multichannel downlink wireless networks [e.g., orthogonal frequency-division multiplexing (OFDM)-based cellular systems with relays]. Over such networks, while it is well understood that the BackPressure algorithm is stabilizing (i.e., queue lengths do not become arbitrarily large), its performance (e.g., delay, buffer usage) can be poor. In this paper, we study an alternative--the MaxWeight algorithm--variants of which are known to have good performance in a single-hop setting. In a general relay setting, however, MaxWeight is not even stabilizing (and thus can have very poor performance). In this paper, we study an iterative MaxWeight algorithm for routing and scheduling in downlink multichannel relay networks. We show that, surprisingly, the iterative MaxWeight algorithm can stabilize the system in several large-scale instantiations of this setting (e.g., general arrivals with full-duplex relays, bounded arrivals with half-duplex relays). Furthermore, using both many-channel large-deviations analysis and simulations, we show that iterative MaxWeight outperforms the BackPressure algorithm from a queue-length/delay perspective.

Channel-Aware Medium Access Control in Multichannel Cognitive Radio Networks

Distributed medium access control (MAC) is important for efficient exploitation of spectrum opportunities in cognitive radio networks. This letter proposes a channel-aware distributed MAC protocol for multichannel cognitive radio networks. The transmitting nodes use channel state information to exploit the available multiuser and multichannel diversity, by contending only under relatively favorable channel conditions. Towards this end, each node utilizes a threshold that is dynamically updated according to certain rules. Simulation results corroborate the throughput gains achieved by the proposed protocol.