The Scheduler is a calendar-based reservation system that gives you exclusive access to COSMOS/ORBIT testbed domains during your reserved time slots. Reservations are essential for running experiments — they guarantee that no other user can power on, image, or interact with nodes in your reserved domain during your time.
Access the Scheduler from the Scheduler link in the portal sidebar.
The Scheduler displays a calendar showing all reservations across all testbed domains. You can customize the view using the controls at the top:
View mode — switch between Day view (one day at a time, all domains visible) and Week view (seven days, scrollable). Day view is best for seeing all available domains at a glance; Week view is best for planning ahead.
Time format — toggle between 12h (AM/PM) and 24h format using the button at the top. Your preference is saved in your browser and persists across sessions.
Date navigation — use the left/right arrows to move forward and backward in time. The Today button jumps to the current date. You can also click the date display to open a date picker for jumping to a specific date.
Clock bar — a reference bar at the top shows the current time in three zones: your local timezone, UTC, and COSMOS Eastern Time (US/Eastern). This helps when coordinating with collaborators in different time zones.
Resources — testbed domains are listed vertically on the left side. Each row represents one domain (e.g., grid.cosmos-lab.org, sb1.cosmos-lab.org). Time slots (30-minute intervals) are arranged horizontally. Hover over a domain name to see a tooltip with its description and location.
Past time slots are grayed out and cannot be clicked. Only future slots can be reserved.
The Scheduler uses distinct colors to help you quickly identify reservation ownership and status at a glance:
| = Color = | = Meaning = |
|---|---|
| Green | Your approved reservation — confirmed and ready to use. You will have full access to the testbed domain during this time. |
| Purple | Your pending reservation — submitted, waiting for automatic or manual approval. |
| Blue | Another user's approved reservation — this slot is taken. |
| Yellow | Another user's pending reservation — not yet confirmed, you may compete for this slot. |
| Red | Conflict — overlapping pending reservations from different users. The auto-approver will resolve this based on the fairness algorithm. |
| Dark gray | Blackout period — the testbed is unavailable, typically for planned maintenance. |
| Orange | Scheduled maintenance window — testbed may be partially available. |
To create a new reservation:
1. Click an empty time slot on the calendar for the resource you want. The slot must be in the future (not grayed out) and not already occupied by another user's approved reservation.
2. Configure the reservation in the dialog that appears:
3. Click Submit to create the reservation.
Your new reservation appears immediately on the calendar as pending (purple). It will progress to approved (green) based on the automatic approval schedule described below.
All domains are approved automatically — no human is in the loop unless there is a dispute. Two mechanisms process pending reservations:
* Daily cycle — once a day (midnight Eastern Time), the scheduler looks at the next 24 hours and approves each user's earliest pending slot per domain. Every user is guaranteed their first slot of the day; additional slots are deliberately left pending so one user cannot claim a whole day in advance.
* Just-in-time approval — every other pending reservation is approved automatically about 90 seconds before its start time, if the slot is still free. There is no per-day limit on just-in-time slots, so you can stack consecutive reservations — they simply confirm one at a time as they begin.
If there are no conflicts, approval requires no action from you: submit, and the slot will turn green either after the nightly cycle or just before it starts.
If another user has a pending reservation on a time slot you want:
1. Click on their reservation (shown in yellow)
2. Select Compete for this slot
3. Your competing reservation is created with the same time range
When multiple users compete for the same slot, the auto-approver resolves the conflict using a fairness algorithm:
* Priority is inversely proportional to the testbed hours each user has consumed over the past 28 days — users with fewer recent hours win
* The losing reservation is trimmed to the nearest 30-minute boundary (or cancelled if nothing usable remains); with a large priority gap the overlap is split proportionally
* This prevents any single user from monopolizing popular testbed resources
Best practice: submit competing reservations at least 2 hours before the slot begins. Conflicts arising less than 2 hours before the start may not be resolved before the slot starts.
You cannot compete for slots that another user has already had approved. Only pending (yellow) reservations can be contested.
Click on any of your reservations to view its details. You can:
Edit — change the start time, end time, participants, or summary. Note that editing a reservation resets its status to pending and it must go through the approval process again. If you are making a minor time adjustment to an already-approved reservation, be aware that it will temporarily lose its approved status.
Cancel — remove a single reservation. The time slot immediately becomes available for other users. Canceled reservations cannot be recovered. A reservation that has already started can only be cancelled within its first 10 minutes (so a booking mistake can be undone, but a mostly-used slot cannot be released to dodge the usage accounting).
Delete Series — if the reservation is part of a recurring series, you can cancel all future occurrences at once while preserving past records.
The My Reservations page (accessible from the sidebar under Scheduler) provides a consolidated view of all your reservations:
* Usage summary — total reservation hours over the last 28 days (the same window the fairness algorithm sees), helping you track your utilization
* Reservation table — a sortable list of all your upcoming and recent reservations showing the resource name, start/end time, duration, status, and any invited users
* Quick cancel — each reservation row has a cancel button for immediate removal
This page is particularly useful when you have multiple reservations across different domains and want to manage them all in one place.
Reservation limits are set per domain. Current values (shown live in the reservation dialog):
| = Resource = | = Description = | = Min = | = Max = |
|---|---|---|---|
| grid.cosmos-lab.org | Main 400-node indoor grid (ORBIT) | 30 min | 2 hours |
| indoor.cosmos-lab.org | Indoor deployment at WINLAB | 30 min | 4 hours |
| sb1.cosmos-lab.org | COSMOS Sandbox 1 (NJ) — SDR / FR3 | 30 min | 6 hours |
| sb2.cosmos-lab.org | COSMOS Sandbox 2 (Columbia University, NYC) | 30 min | 6 hours |
| sb4.cosmos-lab.org | RF attenuator matrix (topology control) | 30 min | 2 hours |
| sb5.cosmos-lab.org | SDR sandbox (USRP B210 pair) | 30 min | 2 hours |
| sb6.cosmos-lab.org | SDR sandbox (USRP X310 pair) | 30 min | 2 hours |
| sb7.cosmos-lab.org | SDR sandbox (USRP N210, SBX daughterboards) | — | 4 hours |
| sb9.cosmos-lab.org | Wired / SDN development | 30 min | 2 hours |
| bed.cosmos-lab.org | COSMOS main deployment (West Harlem, NYC) | 30 min | 6 hours |
| weeks.cosmos-lab.org | Weeks Hall — Industry 4.0 setup (NJ) | 30 min | 6 hours |
| minicity.cosmos-lab.org | Scaled-model smart intersection (ORBIT room, NJ) | 30 min | 6 hours |
| license.cosmos-lab.org | Shared license server allocation | 30 min | 6 hours |
If you need longer access for multi-day experiments, contact testbed support at problems@cosmos-lab.org.