Remote Music Collaboration Using Multi-Edge Audio Sync and Network API

Today, there are about 2 million professional music creators (songwriters, performing artists, and musicians) in the US alone collaborating in person, and another 14.6 million semi-professional creators working remotely via software tools. Current remote music collaboration is asynchronous and does not have the same feeling as when creators are physically in the same room in real-time. This limits the type of virtual multi-artist collaboration possible and increases costs for the label or music activities.

Open Sesame Media is a business-to-business Communication Platform as a Service providing low-latency synchronized audio over 5G to music creators via its patent-pending SyncStage platform. SyncStage allows music creators to immediately access live, remote audio sources directly in their Digital Audio Workstation (DAW) that they use every day (e.g., Ableton, Logic Pro, ProTools, etc). For the optimal user experience, SyncStage needs consistent network performance across round-trip latency, jitter, and packet loss. However, meeting those stringent application requirements is difficult without an enhanced mobile and cloud architecture.

This post demonstrates an optimized SyncStage solution built on multi-AWS Wavelength Zones embedded within the Verizon 5G network and Verizon 5G “Quality of Service on Demand” (QoS) API for the optimal experience of music collaboration across geographical locations. We describe the solution approach in this demo and how the enhanced solution enables audio synchronization applications. We share our initial performance studies with quantitative data and show how the Verizon QoS API and multi-edge cloud computing can deliver higher performance consistency for remote music collaboration as compared to the existing solution.

Remote Music Collaboration and Performance Needs

Figure 1. Remote Music Collaboration with Audio Constraints

Remote music collaboration refers to cases where songwriters or music instructors collaborate, jam, or educate across multiple musical instruments in different geographic locations. Even though they collaborate from different locations in the same metropolitan area or different cities, the experience resembles that of being within the same room. The remote music collaborators’ experience may vary depending on the level of audio synchronization performance, as shown in the following table.

Table 1. Performance Needs for Remote Music Collaboration

Demo Solution Approach and Architecture

The optimization of mobile network services and cloud services is needed to meet the audio synchronization performance objectives quantified in the previous table. For this demo, we use QoS mechanisms in mobile networks and the cloud edge service for consistent performance of lower latency, jitter, and packet loss rate. The following figure shows a reference architecture for audio synchronization applications. This demo solution architecture builds on four technologies: multi-AWS Wavelength Zones embedded in the Verizon 5G network, SyncStage technology, Verizon mobile network QoS API, and Verizon’s network interconnect of AWS Wavelength Zones.

Figure 2. Solution Architecture

1. SyncStage technology

The Open Sesame SyncStage software allows application developers to create synchronous, ultra-low audio latency audio experiences within their applications to enable their users to collaborate with others in real-time. It consists of four major components:

• SyncStage Backend: Built on Amazon API Gateway and AWS Lambda the Backend enables session control across all participating devices during a session.
• Studio Server: Deployed on Amazon Elastic Compute Cloud (Amazon EC2) instances, the Studio Server streams content to and from the connected devices.
• SyncStage Software Development Kit (SDK): A software only SDK for application developers to integrate SyncStage into their application, which provides ultra-low audio latency to a group of users to enable a vast range of synchronized audio experiences.
• SyncStage Test App: Mobile or Web application using SyncStage SDK for demonstrating its low-latency capabilities.

2. AWS cloud-edge zones

AWS extends its cloud infrastructure and services from Region to Edge to support applications with different timing constraints or data residency needs with the same “look and feel” for cloud services. AWS Wavelength is one of AWS Hybrid Edge services that is embedded in Communication Service Providers’ (CSP) public 5G networks. An AWS Wavelength Zone and its parent AWS Region are inter-connected in one Amazon Virtual Private Cloud (Amazon VPC).

In the solution architecture for this demo, each AWS Wavelength Zone in the Verizon 5G network hosts a SyncStage Studio Server to serve SyncStage application clients in a metropolitan area, such as Los Angeles or Las Vegas. The SyncStage application client runs in user equipment (UE), such as an iPhone or Android phone, which is connected with a music instrument such as a guitar. Each SyncStage application client is connected to the SyncStage server in proximity through the Carrier Gateway (CGW) in the AWS Wavelength Zone. The communication between two AWS Wavelength Zones (such as Los Angeles and Las Vegas) is through their parent AWS Region(s) (the Oregon us-west-2 Region in this example). Additionally, a CSP that deploys AWS Wavelength may provide inter-Wavelength Zone connectivity as we describe in the following. An AWS Region (the us-east-1 N. Virginia Region shown in the previous figure) hosts the centralized SyncStage Backend. The SyncStage Backend manages all the Studio Server instances in the AWS Wavelength Zones. In addition, it interfaces with the Verizon QoS API service, invoking QoS API calls upon request from the SyncStage application clients.

3. Verizon mobile network QoS API

Verizon’s QoS API is one of the services developed for the demo, which was designed specifically to leverage the capabilities of the 5G network. The implementation is based on the QoS specification by CAMARA, an open-source project within Linux Foundation. The API allows applications to request and establish an enhanced QoS on demand. Accordingly, the Verizon QoS API service provisions the QoS through the establishment of a dedicated bearer session. This is a specific network path for the QoS between the device (user equipment) and the application endpoint. The establishment of a dedicated bearer takes place through a series of interactions among various 5G core and radio network elements. The detailed network call flow can be found in the 3GPP TS 23.502 specification.

Verizon has recognized the intrinsic value of standardizing Network APIs and has taken significant steps by participating and contributing to GSMA, CAMARA, and 5GFF forums to remove the complexities traditionally associated with telecommunications services. This benefits the developer community at large, providing them with streamlined and user-friendly APIs that abstract the intricacies of the telecommunications network. The common interface created as a result of standardization efforts is likely to accelerate innovation and ease the integration of telecommunication services into many different applications.

4. Verizon network interconnect of cloud-edge zones

The collaboration between Verizon and AWS has led to the deployment of 19 AWS Wavelength Zones across various edge locations, marking a significant advancement in the cloud and networking domains. As shown in the previous figure, the sites are interconnected through Verizon’s advanced transport fabric, making sure data communication between AWS Wavelength Zones is contained within the network. This effectively diminishes latency and augments the overall reliability of the service. This edge network architecture is a game-changer for distributed applications, as it facilitates unprecedented site-to-site low latency. Applications that need real-time data synchronization could benefit greatly from this infrastructure.

With the four technologies introduced previously, let us now see how they support an audio synchronization application together, from audio session set up to audio traffic flow between remote music collaborators. To initiate a remote collaboration, a musician launches an application equipped with an integrated SyncStage SDK, initiating an audio session. Utilizing the SDK’s ‘Create session’ method, the application registers the session in the AWS Region’s serverless, AWS Lambda Function-based SyncStage Backend. This backend not only links the application to the optimal Studio Server on the AWS Wavelength Zone within the Verizon 5G network, but also triggers the Verizon QoS API. In turn, the Verizon QoS service allocates a low-latency QoS bearer along the mobile network path between the UE and the Verizon mobile core. Once the audio session is established with the provisioned QoS bearer, the audio data stream seamlessly flows between the UE and its corresponding SyncStage Studio Server in the AWS Wavelength Zone in the Verizon mobile network.

When another musician joins the session, their application follows a similar flow. Depending on the musician’s location, they can be connected to either the same or a different SyncStage Studio Server. The SyncStage Backend is tasked with handling both scenarios. If users are connected through different Studio Servers, then these servers are interconnected between the hosting AWS Wavelength Zones through Verizon’s network backbone for optimal performance.

Demo Solution Testing and Results

1. Measuring the QoS impact on the network performance

To evaluate the performance of the SyncStage solution enhanced with the Verizon QoS API, two testing locations were strategically chosen within the highly utilized Verizon C-band network cells in Los Angeles and Las Vegas. Tests were conducted during anticipated network congestion peaks to assess the efficacy of the QoS API in mitigating varying latency and jitters associated with high network traffic.

In both locations, we utilized iPhone 13s or newer models, each equipped with the SyncStage Test App. The app was connected to the nearest Studio Servers deployed in the Los Angeles AWS Wavelength Zone and Las Vegas AWS Wavelength Zone, respectively. To ensure data quality, test sessions were conducted with and without QoS, during which packet round trip latency and jitter data were collected.

The test results unequivocally demonstrate that the QoS has a significant impact on reducing network latency and jitter in congested cells. The following figure depicts packet latency fluctuations over time, comparing scenarios with and without QoS for a C-band network cell in Las Vegas. Notably, with QoS, latency fluctuations are considerably less severe than in its absence. Figure 4 provides a packet round trip latency histogram, showing the impact of QoS on latency distribution. With QoS, the latency distribution is markedly narrower, indicating reduced jitter. Additionally, the average latency is significantly lower with the QoS enabled.

Figure 3. Packet Round Trip Latency (ms) over Test Time

Figure 4. Packet Round Trip Latency Distributions with and without QoS

2. Measuring the latency between AWS Wavelength Zones

To make sure of minimal communication speed between the Studio Servers deployed in the Los Angeles AWS Wavelength Zone and Las Vegas AWS Wavelength Zone, we conducted latency tests between these two servers. As shown in Figure 2, one server in one AWS Wavelength Zone issues an Internet Control Message Protocol (ICMP) ping to the Carrier IP address of the server in the other AWS Wavelength Zone. The ping data show that the ping round trip latency between the two servers is consistently in the single-digit milliseconds with variations within sub milliseconds.

The test results clearly show the efficiency of utilizing the Verizon network backbone for inter-Wavelength Zone communications. This approach, routing traffic inside Verizon’s core network significantly reduces latency within the AWS Wavelength environment.

Conclusions

Remote music collaboration use cases need audio communication performance consistency with ultra-low latency and low-jitter. This demo shows that the Verizon QoS API and multiple AWS Wavelength Zones enable Open Sesame Media’s audio synchronization SyncStage software to deliver consistent 5G network performance for music collaborators in different geographical locations.

To learn more about SyncStage, visit the SyncStage website. You may develop your audio synchronization applications using SyncStage SDK. Use AWS Wavelength service embedded in Verizon’s 5G mobile networks for ultra-low latency applications.