An ALM Model for Streaming Media Service in P2P-SIP Network

Application layer multicast (ALM) has been widely applied in Internet, as a substitute for IP multicast. However, it causes network load to increase because it adopts unicast in data transmission, which limits the application. In this article, in order to improve the ALM performance in P2P-SIP network, an ALM model was proposed which reduced network load via merging messages in concast mode. Finally network simulations prove that this model has better benefit on single node load and average network load. Therefore, it is suitable for streaming media service in P2P-SIP Network.

Rate control for streaming media transmission over WLAN

In order to solve the problems of link layer retransmission and packet fragment strategies for IEEE 802.11,this paper proposes a variable packet TCPfriendly rate control(VPTFRC)scheme for streaming media transmission over wireless local area network(WLAN)by researching on the policy of packet size adjustment in transport layer based on the minimum retransmit-delay constraint.Unlike other proposals,this process considers the impact of wireless packet error ratio(PER)on the packet size adjustment and the performance of rate control.Simulation results demonstrate that our proposed process can simultaneously achieve higher throughput,better fairness,shorter transmission delay and less jitter than TFRC.Among them,the ratio of delay,jitter and packet loss rate can reach a maximum improvement ratio of 58%,42% and 85% respectively.

Chemical simulation teaching system based on virtual reality and gesture interaction

Background Most existing chemical experiment teaching systems lack solid immersive experiences,making it difficult to engage students.To address these challenges,we propose a chemical simulation teaching system based on virtual reality and gesture interaction.Methods The parameters of the models were obtained through actual investigation,whereby Blender and 3DS MAX were used to model and import these parameters into a physics engine.By establishing an interface for the physics engine,gesture interaction hardware,and virtual reality(VR)helmet,a highly realistic chemical experiment environment was created.Using code script logic,particle systems,as well as other systems,chemical phenomena were simulated.Furthermore,we created an online teaching platform using streaming media and databases to address the problems of distance teaching.Results The proposed system was evaluated against two mainstream products in the market.In the experiments,the proposed system outperformed the other products in terms of fidelity and practicality.Conclusions The proposed system which offers realistic simulations and practicability,can help improve the high school chemistry experimental education.

Power Allocation for Video Segment Based Caching Strategy in F-RAN Architecture

The concept of edge network caching has been proposed to alleviate the excessive pressure on the core networks.Furthermore,video segment caching technology,a method to cut the whole video into segments and cache them separately,has brought a novel idea to solve the caching problem in the smaller space for massive data.The adoption of segment caching in edge networks will divide the simple video transmission process into two coupling stages because of separate data caching,which leads to more complicated resource allocation.In this paper,this problem is discussed,and its mathematical model is established to minimize the energy consumption of video transmissions.By introducing an efficient prediction window of channel fading,an optimal dynamic scheduling algorithm based on Qlearning is proposed to minimize power consumption while ensuring smooth video streaming.The proposed Q-learning algorithm is simulated and the impacts of channel state,target video bit rate and largescale channel parameter are evaluated.Simulation results show that the proposed method can effectively reduce the total power consumption while ensuring the smooth playback of video service,thanks to the fact that the proposed method is intelligent which can effectively utilize idle resources in favorable channel states.