  In network slicing, the network operator needs to satisfy the service level
agreements of multiple slices at the same time and on the same physical
infrastructure. To do so with reduced provisioned resources, the operator may
consider resource sharing mechanisms. However, each slice then becomes
susceptible to traffic surges in other slices which degrades performance
isolation. To maintain both high efficiency and high isolation, we propose the
introduction of hypothesis testing in resource sharing. Our approach comprises
two phases. In the trial phase, the operator obtains a stochastic model for
each slice that describes its normal behavior, provisions resources and then
signs the service level agreements. In the regular phase, whenever there is
resource contention, hypothesis testing is conducted to check which slices
follow their normal behavior. Slices that fail the test are excluded from
resource sharing to protect the well-behaved ones. We test our approach on a
mobile traffic dataset. Results show that our approach fortifies the service
level agreements against unexpected traffic patterns and achieves high
efficiency via resource sharing. Overall, our approach provides an appealing
tradeoff between efficiency and isolation.
