Bandwidth-Constrained Aerial Edge Perception for Ground Traversability Mapping over Digital Links

Bandwidth-limited aerial–ground sensing requires an explicit trade-off among payload size, decoded-map quality, and downstream route utility. This paper evaluates a strict RGB-D edge-perception interface in which the receiver accesses only a quantized C × 16 × 16 tensor and no encoder-side skip features. Under a fixed AeroScapes protocol, five-seed latent-8 training gives a test intersection over union (IoU) of 0.5617 ± 0.0585 and route utility of 0.0539 ± 0.0227; the strongest validation-selected checkpoint reaches an IoU of 0.6584 but is reported only as a checkpoint-specific result. Acontrolled five-seed width ablation identifies a Pareto set: latent-8 is the lowest-rate operating point at 16.448 kbit, latent-16 has the smallest IoU standard deviation, and latent-32 gives the highest mean IoU (0.5788) and route utility (0.0921), with no significant pairwise differences between widths. A paired threeseed stabilization test likewise finds no significant IoU improvement from depth dropout, a soft topology loss, or their combination (p ≥ 0.6060); the combined configuration raises mean IoU to 0.5700 but increases dispersion. Relative to a practical reference combining JPEG (quality 75) RGB and 8-bit PNG depth, latent-8 reduces the mean payload by a factor of 4.32. The digital-link study extends the additive-noise analysis to fading, intersymbol interference, timevariation, packet and burst errors, near–far interference, and corrupted range metadata. Conventional short codes, source-aware unequal protection, and a 3GPP NR LDPC implementation are evaluated with framing, automatic repeat request, mediumaccess overhead, and transmission delay. Cross-domain evaluation establishes an important limitation: zero-shot AeroScapes-to-UAVid transfer is weak, whereas sequence-disjoint tenseed UAVid training improves the eight-class mean IoU from 0.2417 ± 0.0221 for RGB-only to 0.2602 ± 0.0129 for strict RGB-D (p = 0.0161). Lightweight depth, visibility, missingdepth, weighted-topology, and coarse-to-local refinement experiments further delimit deployment. Together, these experiments provide an auditable cross-layer evaluation linking source representation, channel reliability, protocol cost, spatial error, and receivergrid connectivity without equating one favorable checkpoint with general superiority.