Paper presented at EICS '22: https://dl.acm.org/doi/10.1145/3532210 The "Software as a Service" (SaaS) model of cloud computing popularized online multiuser collaborative software. Two famous examples of this class of software are Office 365 from Microsoft and Google Workspace. Cloud technology removes the need to install and update the software on end users' computers and provides the necessary underlying infrastructure for online collaboration. However, to provide a good end-user experience, cloud services require an infrastructure able to scale up to the task and allow low-latency interactions with a variety of users worldwide. This is a limiting factor for actors that do not possess such infrastructure. Unlike cloud computing which forgets the computational and interactional capabilities of end users' devices, the edge computing paradigm promises to exploit them as much as possible. To investigate the potential of edge computing over cloud computing, this paper presents a method for engineering interactive collaborative software supported by edge devices for the replacement of cloud computing resources. Our method is able to handle user interface aspects such as connection, execution, migration, and disconnection differently depending on the available technology. We exemplify our approach by developing a distributed Pictionary game deployed in two scenarios: a nonshared scenario where each participant interacts only with their own device and a shared scenario where participants also share a common device, including a TV. After a theoretical comparative study of edge vs. cloud computing, an experiment compares the two implementations to determine their effect on the end user's perceived experience and latency vs. real latency

1. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
Engineering the Transition of Interactive Collaborative
Software from Cloud Computing to Edge Computing
Guillaume Ortegat, Donatien Grolaux, Etienne Rivière, Jean
Vanderdonckt

2. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Cloud computing
● Exchange message only with the server
● State managed by the server

3. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Cloud computing: Cloud Latency and Model Limitation
Bandwidth hardware limitation Unexploited ressources
No device adaptation No user situation adaptation

4. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Edge computing
● Migrate the hosting task on the user device
● Peer-to-peer communication between devices
● Small cloud server

5. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Traffic controller
Server part
User
Client part
User
Client part
Disconnection
mechanism
Drawing
mechanism
Connection
mechanism
Guessing
mechanism
Client part
Cloud computing
Overall
structure
Components
structure
Edge computing
User
Client part
Server part
User
Client part
Drawing
mechanism
Hosting
mechanism
Guessing
mechanism
Disconnection
mechanism
Connection
mechanism
Client part

6. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Transition from Cloud to Edge computing
● Modified mechanisms : connection, drawing, guessing, disconnection
● Added mechanism : migration of the hosting part

7. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Application example: distributed Pictionary
User role
Display role
Drawing role

8. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
User 1 User 2 User 3
User 1
User 2
User 3
User 1
User 3
Non-shared scenario

9. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
● Vidéo scénario séparé
Tablet
Shared
Used
by
User 2
TV
shared
User 1 User 2 User 3
Tablet
Shared
Used
by
User 1
User 1 User 2 User 3
Shared scenario

10. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Evaluation
2 groups of 5 people
Game configurations
8 2 30.3 years Daily All except one
Cloud
0 ms
Cloud 80
ms
Cloud 300
ms
Edge
Shared scenario S0 S80 S300 SE
Non-shared
scenario
N0 N80 N300 NE
Protocol
1. Consent form
2. Acclimatation
3. Playing all the configurations
4. Answer questions after each game

11. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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0 100 200 300 400 500 600
Shared - Edge (SE)
Non-shared - Edge (NE)
Non-shared - Cloud 300 (N300)
Non-shared - Cloud 80 (N80)
Shared - Cloud 300 (S300)
Non-shared - Cloud 0 (N0)
Shared - Cloud 0 (S0)
Shared - Cloud 80 (S80) 138.42
60.86
64.14
439.13
117.01
12.25
30.11
Latency measured [msec]
Real latency
✱✱✱✱ ✱✱
✱✱✱✱
1 2 3 4 5 6 7
Shared - Edge (SE)
Non-shared - Edge (NE)
Non-shared - Cloud 300 (N300)
Non-shared - Cloud 80 (N80)
Shared - Cloud 300 (S300)
Non-shared - Cloud 0 (N0)
Shared - Cloud 0 (S0)
Shared - Cloud 80 (S80) 5.90
5.56
4.90
4.90
4.67
4.30
4.22
3.40
Rating scale [1..7]
Condition
[Code]
✱
Perceived latency
Condition [Code] Perceived latency Real latency
****
**
****
****
****

12. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Informal User Comments
Many players have difficulty
seeing the difference
between game
configurations
Players did not notice the
server was shut down during
a game
Some players express fun
to play and aim the victory

13. ACM EICS ‘22 (Sophia Antipolis, June 21-24, 2022)
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Conclusion
• Low latency
• Server failure tolerant
• Level of service equivalent to cloud
• Take advantage of edge device
• Adaptation of each application requires
a specific architecture
• Librairies presents few shortcomings