Wireless access to encoded video requires sophisticated error resilient mechanisms. Although some video coding standards describe error resilience algorithms, they are inefficient at deep fading wireless and mobile channels. In this paper, we present a novel scheme of error protection for narrowband wireless channels which is independent of any video coding standard. Being, however, this scheme common to all standards, it provides some acceptable video quality degradation. We have evaluated the quality degradation of the Common solution in comparison to the optimal scheme of protection corresponding to the existence of a finite number of channel codes. Besides, we also present the quality degradation for both video coding standards, H.263 and MPEG-4, obtained from a finite number of codes in comparison with the ideal scheme corresponding to the existence of an infinite number of channel codes. Additionally, we proposed a protection solution tailored to H.263/MPEG-4 source coding with an average PSNR improvement of about 0.2 dB relatively to the above mentioned Common solution. Thus, in the framework of joint source-channel coding, we present an adaptive scheme of protection according to the channel bit error rate (BER) and with an overall transmission rate of 64 kbps. In our investigation, we used four QCIF video test sequences and rate compatible punctured convolutional (RCPC) codes. For instance, a PSNR gain of about 16.7 dB is obtained at BER=10-2 for 'Foreman' video sequence, encoded either by H.263 or by MPEG-4 and protected using the Common scheme in comparison to the unprotected case.