# Supporting Immersive Video Streaming via V2X Communication
## 2 Bandwidth Allocation for Diverse Streaming Services in V2X Communication
### Bandwidth Allocation for Non-Real-Time Applications
\(sl_{s}^{\sigma,v}\) represents the time duration of downloading video segment \(s\) of \(v\). \(dvr_{\tau_{s}^{\sigma,v}}^{B}\) and \(dvr_{\tau_{s}^{\sigma,v}}^{E}\) indicate the resolutions of the base and enhancement layers of \(v\), respectively, while \(\mathrm{fr}^{\sigma,v}\) denotes the frame rate per second. \(CurTime\) is the current time, \(spt^{\sigma,v}\) and \(ept^{\sigma,v}\) stand for the start and end times of playing \(v\), respectively, \(\varrho\) is the lower limit of traffic flow that indicates the road segment is congested, and \(\rho_{\delta_{t}^{\sigma},\delta_{t+1}^{\sigma,v}}\) represents the traffic flow connecting road sections \(c_{i}^{\sigma}\) and \(c_{i+1}^{\sigma}\). \(vl_{\sigma_{s}^{\sigma,v}}\) is the resolution requirement for the \(\kappa^{\sigma,v}\) level of video screen set by the vehicle passenger, and \(buf^{\sigma,v}\) represents the pre-downloaded video segments stored in the buffer. * Examine whether the CF XL-MIMO access points from the previous step can meet the minimum bandwidth requirements for the base and enhancement layers of \(v\) as follows: \[\delta_{\tau_{\varsigma}^{\sigma,v}}\cdot\Delta\cdot\sum_{\emptyset\sigma^{ \prime}}db_{\tau_{\varsigma}^{\sigma,v}}^{\sigma,v}\geq sl_{\varsigma}^{\sigma,v}\cdot\left(dvr_{\overline{t}_{\varsigma}^{\sigma,v}}^{\beta}+dvr_{\overline{ t}_{\varsigma}^{\sigma,v}}^{\varepsilon}\right)\cdot\text{f}^{\sigma,v},\quad 1 \leq\delta_{\tau_{\varsigma}^{\sigma,v}},\;is^{\sigma,v}\leq s\leq\overline{s}^{ \sigma,v},\]1 (46) where \(dpt^{\sigma,v}\) is the time duration of pre-downloaded video \(v\) stored in the buffer. * If \(dpt^{\sigma,v}\geq 0\), it indicates that the required bandwidth for both the base and enhancement layers of \(v\) can be pre-downloaded. In this case, the CF XL-MIMO access point control unit is notified, and the result is returned to the vehicle passenger, concluding the execution of this module. Otherwise, proceed to the next step. * Calculate the bandwidth available for the remaining travel distance of the non-real-time application based on the specifications of the base layer \(\varpi\): \[\delta_{\tau_{\varsigma}^{\sigma,v}}\cdot\Delta\cdot\sum_{\emptyset\sigma^{ \prime}}db_{\tau_{\varsigma}^{\sigma,v}}^{\sigma,v}\geq sl_{\varsigma}^{\sigma,v}\cdot\left(dvr_{\overline{t}_{\varsigma}^{\sigma,v}}^{\beta}+dvr_{\overline{ t}_{\varsigma}^{\sigma,v}}^{\varepsilon}\right)\cdot\text{f}^{\sigma,v},\quad 1 \leq\delta_{\tau_{\varsigma}^{\sigma,v}},\;is^{\sigma,v}\leq s\leq\overline{s}^{ \sigma,v},\]2 (47) The above equation depends on: \[\delta_{\tau_{\varsigma}^{\sigma,v}}\cdot\Delta\cdot\sum_{\emptyset\sigma^{ \prime}}db_{\tau_{\varsigma}^{\sigma,v}}^{\sigma,v}\geq sl_{\varsigma}^{\sigma,v}\cdot\left(dvr_{\overline{t}_{\varsigma}^{\sigma,v}}^{\beta}+dvr_{\overline{ t}_{\varsigma}^{\sigma,v}}^{\varepsilon}\right)\cdot\text{f}^{\sigma,v},\quad 1 \leq\delta_{\tau_{\varsigma}^{\sigma,v}},\;is^{\sigma,v}\leq s\leq\overline{s}^{ \sigma,v},\]3 (48) Equations (37)-(45)
* If the previous step can meet the bandwidth requirements for the base layer of \(v\), then notify the CF XL-MIMO access point control unit to provide the required bandwidth for the base layer to the vehicle, and return the result to the vehicle passenger, concluding the execution of this module. Otherwise, continue to the next step. * If the vehicle passenger is categorized as a regular user, proceed to Step 9. * Consult the RSU of the remaining road segments along the route to reallocate the bandwidth originally assigned to non-real-time applications of regular users to premium users.